Ancient mantle in a modern arc: osmium isotopes in izu-bonin-mariana forearc peridotites

Mantle peridotites drilled from the Izu-Bonin-Mariana forearc have unradiogenic 187Os/188Os ratios (0.1193 to 0.1273), which give Proterozoic model ages of 820 to 1230 million years ago. If these peridotites are residues from magmatism during the initiation of subduction 40 to 48 million years ago, then the mantle that melted was much more depleted in incompatible elements than the source of mid-ocean ridge basalts (MORB). This result indicates that osmium isotopes record information about ancient melting events in the convecting upper mantle not recorded by incompatible lithophile isotope tracers. Subduction zones may be a graveyard for ancient depleted mantle material, and portions of the convecting upper mantle may be less radiogenic in osmium isotopes than previously recognized.     

Feeding value of wheat-based thin stillage: in vitro protein degradability and effects on ruminal fermentation.

Two experiments were conducted to evaluate the nutritive value of wheat-based thin stillage as a fluid source for ruminants. In vitro CP degradability of thin stillage was estimated relative to canola meal and heated canola meal in a completely randomized design. Four ruminally cannulated steers were used in a double cross-over design to determine the effects of consuming thin stillage or water as drinking sources on ruminal fermentation traits. The in vitro CP degradability of thin stillage (55.4%) was lower (P<.05) than that of canola meal (59.4%) and higher than that of heated canola meal (31.6%). Ruminal pH for steers consuming thin stillage was higher (P<.05) at 1000 and 1100 and lower (P<.05) at 1900 and 2000 than that for steers consuming water. Total VFA followed a pattern that was the reverse of that reported for pH. Ruminal NH3 N levels were higher (P<.05) for steers fed thin stillage than for water-fed steers through most of the collection period. Ruminal fluid and particulate matter passage rates were not affected by treatment and averaged .165 and .06 /h, respectively. The amount of thin stillage and water that did not equilibrate with the ruminal fluid and, thus, was considered to bypass the rumen was estimated to be 51.9 and 59.2% of total fluid consumed, respectively. Feeding wheat-based thin stillage had no adverse effects on ruminal metabolism.     

A case of trisomy 22 in a live hereford calf.

A case of the rare genetic trisomy 22 in a live calf is described. The calf had low blood thyroxine level and low growth rate. It had several defects including brachygnathia superior, strabismus convergence, aortal cusp insufficiency and hypertrophy of clitoris. Chromosome analysis was performed on cultured blood lymphocytes and fibroblast cells. In all counted metaphases 61 chromosomes were present. The extra chromosome was identified as a chromosome 22 by R-banding. The defects of the calf have similarities with cases of partial trisomy 3p25-pter in human. This section of the human chromosome 3 corresponds to sections of cattle chromosome 22.     

The Relationship between Semen Quality and the Nonreturn Rate of Bulls

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The value of routine evaluation of bull semen was analysed for 117 AI bulls placed in two studs. Data from semen analysis of a total of 1635 ejaculates was compared statistically with the nonreturn rates of the bulls. The semen parameters which were significantly correlated to nonreturn rates were the motility of the freshly collected ejaculates (p = 0.0140) and post-thaw motility (p = 0.0075). The total number of motile sperm in the inseminate ranged from 10.9 to 19.3 × 10⁶ and according to previous reports the effects of low motility should be fully 'compensated' when doses above 10 × 10⁶ sperm/dose are used for insemination. In conclusion, the motility of freshly collected semen does not appear to be 'compensation' and a low percentage of motile sperm in an ejaculate may indicate other dysfunctions of the population of motile cells. Furthermore, post-thaw motility appears to correlate significantly with nonreturn rates. The largest proportion of the variation was explained by the breed of the bull and stud (42.2% of the variation), whereas the two motility parameters explained 10% of the total variation in nonreturn rates. Objective and precise evaluation of sperm motility in combination with other semen traits are needed to improve breeding efficiency. Although microscopic evaluation of sperm motility correlates with nonreturn rates of bulls, the methods are subjectively assessed and inaccurate and therefore do not allow a satisfactory prediction of fertility.     

MEY = MSY

It has been generally accepted for more than half a century that the fishing sector stood to gain from managing fisheries at the effort level producing maximum economic yield (MEY) rather than at the higher effort level producing maximum sustainable yield (MSY). However, the acceptance is built on evaluating only the revenue and cost structure for the fishing fleet, not for the overall fishing sector including processing, distribution and marketing of fish products. Considering these links of the fish value chain moves the MEY-level closer to, but slightly below the MSY-level. For society as a whole, this means that MSY is the more appropriate target reference level.     

A novel small molecule Met inhibitor, PF2362376, exhibits biological activity against osteosarcoma

The receptor tyrosine kinase Met is dysregulated in several human cancers including osteosarcoma (OSA) in which overexpression is a negative prognostic indicator and enforced Met expression in normal osteoblasts leads to genomic instability and malignant transformation. Met is also known to be inappropriately expressed in canine OSA tumour samples and cell lines. The purpose of this study was to evaluate the potential utility of an orally bioavailable small molecule Met inhibitor, PF2362376, against canine OSA cell lines as a prelude to future clinical work. PF2362376 inhibited phosphorylation of Met, Gab‐1, Erk and Akt, but not of Src or STAT3. Furthermore, PF2362376 inhibited proliferation of canine OSA cell lines and induced cell death at biologically achievable concentrations. Last, activities associated with Met signalling including migration, invasion, branching morphogenesis and colony formation in soft agar were blocked by PF2362376. These studies support the notion that Met is a relevant target for therapeutic intervention in OSA.     

Long-term decline and local extinction of Clethrionomys rufocanus in boreal Sweden

Over the past three decades in boreal Sweden, there has been a long-term decline of cyclic sympatric voles, leading to local extinctions of the most affected species, the grey-sided vole (Clethrionomys rufocanus). We monitored this decline by snap-trapping on 58 permanent plots spread over 100 km² in spring and fall from fall 1971–2003. The reason for the decline is largely unknown, although a common major factor is likely to be involved in the decline of C. rufocanus and of the coexisting voles. However, here we deal with the reasonability of one complementary hypothesis, the habitat fragmentation hypothesis, which assumes that part of the decline of C. rufocanus is caused by habitat (forest) destruction. There was considerable local variation in the decline among the 58 1-ha sampling plots, with respect to both density and timing of the decline; however, all declines ended up with local extinction almost without exception. Local declines were not associated with habitat destruction by clear-cutting within sampling-plots, as declines started about equally often before as after clear-cutting, which suggested that habitat destruction outside sampling plots could be involved. In a multiple regression analysis, local habitat preference (LHP; expressed as a ratio of observed to expected number of voles trapped per habitat) together with two habitat variables in the surrounding (2.5×2.5 km²) landscape matrix explained 56% of the variation among local cumulated densities of C. rufocanus and hence of local time-series. LHP was positively correlated and explained 31% of the variation, while connectivity among clear-cuts was negatively correlated and proximity among xeric-mesic mires was positively correlated and explained additional 16% and 9%, respectively. Even if the overall decline cannot be connected to local clear-cutting on sampling-plots, clear-cutting and hence habitat fragmentation/destruction in the surrounding landscapes potentially influenced grey-sided vole numbers negatively.     

Contribution of the seed microbiome to weed management

Seed‐attacking microorganisms have an undefined potential for management of the weed seedbank, either directly through inundative inoculation of soils with effective pathogenic strains, or indirectly by managing soils in a manner that promotes native seed‐decaying microorganisms. However, research in this area is still limited and not consistently successful because of technological limitations in identifying the pathogens involved and their efficacy. We suggest that these limitations can now be overcome through application of new molecular techniques to identify the microorganisms interacting with weed seeds and to decipher their functionality. However, an interdisciplinary weed management approach that includes weed scientists, microbiologists, soil ecologists and molecular biologists is required to provide new insights into physical and chemical interactions between different seed species and microorganisms. Such insight is a prerequisite to identify the best candidate organisms to consider for seedbank management and to find ways to increase weed seed suppressive soil communities.     

Indices of landscape pattern

Landscape ecology deals with the patterning of ecosystems in space. Methods are needed to quantify aspects of spatial pattern that can be correlated with ecological processes. The present paper develops three indices of pattern derived from information theory and fractal geometry. Using digitized maps, the indices are calculated for 94 quadrangles covering most of the eastern United States. The indices are shown to be reasonably independent of each other and to capture major features of landscape pattern. One of the indices, the fractal dimension, is shown to be correlated with the degree of human manipulation of the landscape.     

Effects of diets of high sulphur content and varied concentrations of copper, molybdenum and thiamine on in vitro phagocytic and candidacidal activity of neutrophils in sheep

Candidacidal and phagocytic tests were performed on 34 female sheep fed high sulphur diets containing varied concentrations of thiamine, copper, and molybdenum for 14 weeks. Tests were conducted at weekly intervals for five weeks during the latter half of the experiment. The ability of polymorphonuclear leucocytes from sheep on diets unsupplemented with thiamine to kill phagocytosed Candida albicans was lower than those on diets supplemented with thiamine. The ability of polymorphonuclear leucocytes to phagocytose C albicans was lower in animals on low copper diets than in animals on high copper diets. Factorial analysis showed that thiamine supplementation significantly increased (P less than 0.0001) candidacidal but not phagocytic activity. By contrast, copper supplementation significantly increased (P less than 0.0005) the phagocytic activity with no effect on candidacidal activity. The observed detrimental effect of high sulphur intake on in vitro polymorphonuclear leucocyte function can mean that ruminants in areas where large quantities of sulphur are taken in with water and feed have compromised immune function due to lower copper and thiamine status and hence are at risk of increased susceptibility to infections.