Identification and characterisation of coding tandem repeat variants in incA gene of Chlamydophila pecorum

Bacteria of the family Chlamydiaceae are obligate intracellular pathogens of human and animals. Chlamydophila pecorum is associated with different pathological conditions in ruminants, swine and koala. To characterize a coding tandem repeat (CTR) identified at the 3' end of incA gene of C. pecorum, 51 strains of different chlamydial species were examined. The CTR were observed in 18 of 18 tested C. pecorum isolates including symptomatic and asymptomatic animals from diverse geographical origins. The CTR were also found in two strains of C. abortus respectively isolated from faeces from a healthy ewe and from a goat belonging to asymptomatic herds, but were absent in C. abortus strains isolated from clinical disease specimens, and in tested strains of C. psittaci, C. caviae, C. felis and C. trachomatis. The number of CTR repeats is variable and encode several motifs that are rich in alanine and proline. The CTR-derived variable structure of incA, which encode the Chlamydiaceae-specific type III secreted inclusion membrane protein, IncA, may be involved in the adaptation of C. pecorum to its environment by allowing it to persist in the host cell.     

Global patterns of predator diversity in the open oceans

The open oceans comprise most of the biosphere, yet patterns and trends of species diversity there are enigmatic. Here, we derive worldwide patterns of tuna and billfish diversity over the past 50 years, revealing distinct subtropical "hotspots" that appeared to hold generally for other predators and zooplankton. Diversity was positively correlated with thermal fronts and dissolved oxygen and a nonlinear function of temperature (approximately 25 degrees C optimum). Diversity declined between 10 and 50% in all oceans, a trend that coincided with increased fishing pressure, superimposed on strong El Ni?o-Southern Oscillation-driven variability across the Pacific. We conclude that predator diversity shows a predictable yet eroding pattern signaling ecosystem-wide changes linked to climate and fishing.     

Tractor risk abatement and control as a coherent strategy

The agricultural tractor was the principal source of fatal injury on American farms for the latter part of the 20th century, and they maintain that distinction today. Much has been learned about the toll of these fatalities and how to prevent them over the last ten years, yet public policy has generally been unsuccessful in reducing this toll. A policy conference entitled Tractor Risk Abatement and Control convened in 1997 to develop recommendations to reduce this death toll. Several stakeholders at the conference agreed on 25 action items, which if implemented would reduce the number of tractor-related deaths by more than 2,000 by the year 2015. These recommendations relate to tractor overturns, runovers, and traffic collisions as well as youth operators. This article addresses the completeness of a strategy for preventing tractor-related injuries for each of these four areas based upon an evaluation model derived from the Theory of Planned Behavior and an antecedent model. The ultimate result of this model is to influence an individual's intention to act to prevent injury. The set of recommendations was found to provide a coherent strategy. In addition, implementing the strategy at an organizational level is discussed.     

Prevention effectiveness of rollover protective structures--Part II: Decision analysis

This is the second of three articles that evaluate the consequences of using rollover protective structures (ROPS) on agricultural tractors. It presents the results of a decision analysis that compares three strategies for preventing injuries when agricultural tractors without ROPS overturn. The three strategies examined are "do nothing", "install ROPS", and "replace tractor". The strategies are implemented over a five-year period and health outcomes expressed as fatal and nonfatal injuries are calculated over a 23-year period. The "do nothing" strategy would result in 1,450 fatalities and 1,806 nonfatal injuries, while the "install ROPS" strategy would prevent 1,176 fatalities and 957 nonfatal injuries, and the "replace tractor" strategy would prevent 1,188 fatalities and 967 nonfatal injuries. The latter two strategies reflect more than an 80% reduction in fatalities and about 53% reduction in nonfatal injuries. The study does not consider overturn injuries that result from tractors lacking ROPS and for which ROPS are unavailable.     

The Induction of Tetraploidy in Salmonids

The induction of tetraploidy was attempted in three intraspecies crosses (autotetraploid) of sal-monid: chinook salmon ( Oncorhynchus tshawytscha ), coho salmon ( O. kisutch ) and rainbow trout ( Salmo gairdneri ), and in the interspecies hybrid (allotetraploid) coho × Atlantic salmon ( Salmo salar ).
Pressure treatments of 6.2 × 10⁴ kPa (9,000 psi) were applied for six minutes at intervals from 50% of the time to cleavage to beyond first cleavage. Analysis of eyed stage embryos via flow cytometry indicated two periods of tetraploid induction existed corresponding to 55–75% and 100–110% of the first cleavage interval (FCI).
The effects of different pressures and the times of application were analyzed in a study with rainbow trout. Treatments of 4.8 × 10⁴ kPa (7,000 psi) for eight minutes, and 5.5 and 6.2 × 10⁴ kPa (8,000 and 9,000 psi) for four minutes, were applied at 65, 78, and 100% FCI. Tetraploids were found in the 5.5 and 6.2 × 10⁴ kPa group treatments only when applied at 65% FCI.
The results indicate that, while tetraploidy is inducible in salmonids, further experimentation is necessary to discern the appropriate time and treatment for optimal tetraploid induction in each species.     

Partial purification and characterization of chicken interleukin-2.

Chicken interleukin 2 (IL-2) activity was partially purified from conditioned medium produced by culturing chicken splenic lymphocytes in the presence of concanavalin A. The purification procedure included sequential steps of gel filtration chromatography, reverse-phase high-pressure liquid chromatography, and phenyl-sepharose chromatography. Two peaks of IL-2 activity with apparent mol. wt. ranges of 36-39 kD and 17.5-25 kD were eluted from the Sephadex G100 gel filtration column. An increase in IL-2 spec. act. from 14 U mg-1 to between 2000 and 20,000 U mg-1 was obtained for the Sephadex G100 column peaks when subjected to the subsequent steps of the purification procedure. Alkylative reduction of the higher mol. wt. Sephadex G100 column peak (followed by re-chromatography with Sephadex G100), resulted in generation of the lower (17.5 kD) mol. wt. peak, indicating that chicken IL-2 is capable of either dimerizing or forming aggregates with other proteins. Elution of the lower mol. wt. IL-2 activity from a non-reducing sodium dodecyl sulfate-polyacrylamide gel demonstrated an apparent mol. wt. for chicken IL-2 of 20 kD, which confirmed the range of 17.5-25 kD seen with gel filtration.     

Colostral and milk antibody titers in cows vaccinated with a modified live-rotavirus-coronavirus vaccine

Colostral and milk whey rotavirus (RV) and coronavirus (CV) antibody titers stimulated in 15 beef heifers by vaccination with a modified live-RV-CV vaccine were compared with titers in 15 nonvaccinated heifers. Geometric mean antibody titers to RV in colostral and 3-day milk whey from vaccinated heifers were 2,807 and 92, respectively, and in control heifers were 1,613 and 71, respectively. Geometric mean antibody titers to CV in colostral and 3-day milk whey of vaccinated heifers were 877 and 13, respectively, compared with titers were 877 and 13, respectively, compared with titers in nonvaccinated heifers of 731 and 7, respectively. Differences in antibody titers between vaccinated and nonvaccinated heifers were not significantly different.