Physical activity patterns of free living dogs diagnosed with osteoarthritis

Osteoarthritis (OA) affects about 90% of dogs > 5 yr of age in the United States, resulting in reduced range of motion, difficulty climbing and jumping, reduced physical activity, and lower quality of life. Our objective was to use activity monitors to measure physical activity and identify how activity counts correlate with age, body weight (BW), body condition score (BCS), serum inflammatory markers, veterinarian pain assessment, and owner perception of pain in free-living dogs with OA. The University of Illinois Institutional Animal Care and Use Committee approved the study and owner consent was received prior to experimentation. Fifty-six client-owned dogs (mean age = 7.8 yr; mean BCS = 6.1) with clinical signs and veterinary diagnosis of OA wore HeyRex activity collars continuously over a 49-d period. Blood samples were collected on day 0 and 49, and dog owners completed canine brief pain inventory (CBPI) and Liverpool osteoarthritis in dogs (LOAD) surveys on day 0, 21, 35, and 49. All data were analyzed using SAS 9.3 using repeated measures and R Studio 1.0.136 was used to generate Pearson correlation coefficients between data outcomes. Average activity throughout the study demonstrated greater activity levels on weekends. It also showed that 24-h activity spiked twice daily, once in the morning and another in the afternoon. Serum C-reactive protein concentration was lower (P < 0.01) at day 49 compared to day 0. Survey data indicated lower (P < 0.05) overall pain intensity and severity score on day 21, 35 and 49 compared to day 0. BW was correlated with average activity counts (P = 0.02; r = −0.12) and run activity (P = 0.10; r = −0.24). Weekend average activity counts were correlated with owner pain intensity scores (P = 0.0813; r = −0.2311), but weekday average activity count was not. Age was not correlated with total activity count, sleep activity, or run activity, but it was correlated with scratch (P = 0.03; r = −0.10), alert (P = 0.03; r = −0.13), and walk (P = 0.09; r = −0.23) activities. Total activity counts and activity type (sleep, scratch, alert, walk, and run) were not correlated with pain scored by veterinarians, pain intensity or severity scored by owners, or baseline BCS. Even though the lack of controls and/or information on the individual living conditions of dogs resulted in a high level of variability in this study, our data suggest that the use of activity monitors have the potential to aid in the management of OA and other conditions affecting activity (e.g., allergy; anxiety).     

Low level of selfing found in a sample of crosses in Australian sugarcane breeding programs

In sugarcane breeding programs, parents used in crosses are classified as male or female based on relative amounts of viable pollen produced. Usually the ‘female’ parent produces some pollen, albeit at a lower level than the ‘male’ parent. The possibility of selfing and associated problems have long been recognised by breeders. A high level of selfing may seriously bias estimates of breeding value of parents and affect the reliability of family means for identifying superior crosses. However, there is no reliable information reported indicating the level to which selfing is occurring in sugarcane crosses. The level of selfing was evaluated in eight Australian sugarcane crosses using RAPD markers. The crosses were selected as exhibiting variable levels of performance, as judged by measurements of commercial cane sugar (CCS), cane yield (TCH) and sugar yield (TSH) in plots consisting of random progeny clones. Five to eight male-specific RAPD bands were identified for each cross and used to screen twenty-eight to thirty-eight progeny from each cross. Selfed progeny were identified in each cross on the basis of absence of any male-specific RAPD bands after screening with at least 5 such RAPDs. Levels of selfing ranged from 0 to17.6%, with most of the crosses exhibiting zero or low levels of selfing. Although only a limited number of sugarcane crosses have been studied, this survey suggests that unwanted selfing is not a significant problem in the Australian sugarcane breeding program. This revised version was published online in July 2006 with corrections to the Cover Date.     

An assessment of the genetic relationship between sweet and grain sorghums, within Sorghum bicolor ssp. bicolor (L.) Moench, using AFLP markers

Compared to grain sorghums, sweet sorghums typically have lower grain yield and thick, tall stalks which accumulate high levels of sugar (sucrose, fructose and glucose). Unlike commercial grain sorghum (S. bicolor ssp. bicolor) cultivars, which are usually F₁ hybrids, commercial sweet sorghums were selected as wild accessions or have undergone limited plant breeding. Although all sweet sorghums are classified within S. bicolor ssp. bicolor, their genetic relationship with grain sorghums is yet to be investigated. Ninety-five genotypes, including 31 sweet sorghums and 64 grain sorghums, representing all five races within the subspecies bicolor, were screened with 277 polymorphic amplified fragment length polymorphism (AFLP) markers. Cluster analysis separated older sweet sorghum accessions (collected in mid 1800s) from those developed and released during the early to mid 1900s. These groups were emphasised in a principle component analysis of the results such that sweet sorghum lines were largely distinguished from the others, particularly by a group of markers located on sorghum chromosomes SBI-08 and SBI-10. Other studies have shown that QTL and ESTs for sugar-related traits, as well as for height and anthesis, map to SBI-10. Although the clusters obtained did not group clearly on the basis of racial classification, the sweet sorghum lines often cluster with grain sorghums of similar racial origin thus suggesting that sweet sorghum is of polyphyletic origin within S. bicolor ssp. bicolor     

Forcing of Atlantic Equatorial and Subpolar Millennial Cycles by Precession

Abundance cycles of the marine alga Florisphaera profunda centered on a period of 7600 carbon-14 years (8400 calendar years) are present in high-resolution records from the equatorial Atlantic spanning 0 to 45,000 years ago. These cycles correlate with Heinrich events 1 through 5, which document rapid changes in continental ice melting around the subpolar North Atlantic. These variations in F. profunda are a direct response to modulation in zonal wind-driven divergence produced by a precessional component of orbital variation during a time of reduced eccentricity modulation.     

Phylogeography,genetic stocks,and conservation implications for an Australian endemic marine turtle

1. Identification of the geographic extent of population boundaries, the distribution of genetic lineages, and the amount of genetic exchange among breeding groups is needed for effective conservation of vulnerable marine migratory species. This is particularly true of the flatback turtle (Natator depressus), which only breeds in Australia but has extensive migrations that can include international waters.
2. This study investigated the phylogeography and genetic structure among 17 flatback turtle rookeries across their range by sequencing an 810 bp portion of the mitochondrial DNA in 889 samples and genotyping 10 microsatellite loci in 598 samples.
3. There was low phylogenetic divergence among haplotypes and evidence of recent population expansion, likely in the late Pleistocene. A predominant haplotype was found across all rookeries, but other haplotype groups were regionally specific.
4. In general, there was agreement in patterns of genetic differentiation in the mitochondrial DNA and microsatellite data, and in some pairwise comparisons a higher mutation rate of microsatellites provided stronger evidence of differentiation.
5. These results suggest natal philopatry operates in the choice of breeding locations for males as well as females.
6. Evidence of genetic connectivity among neighbouring rookeries led to the identification of seven genetic stocks. Geographic boundaries of rookeries used by genetic stocks varied widely (160–1,300 km), highlighting a need for field studies to better understand movement patterns.
7. Hierarchical analysis of molecular variance identified significant genetic differentiation based upon genetic stock, nesting phenology (summer vs. winter nesters), and a west–east discontinuity across Torres Strait. A pattern of isolation by distance was identified, which was most strongly observed in the microsatellite data.
8. In combination with tagging and telemetry studies, these results will allow better quantification of stock‐specific threats along migratory routes and in foraging habitats. Implications of climate change will be stock specific and may depend upon the extent of genetic connectivity between neighbouring stocks.

     

Scanning electron microscope observations of the development of sporophores ofColletotrichum atramentarium (B. et Br.) Taub. on infected potato periderm

Sections of potato periderm (1cm²), bearing sclerotia ofC. atramentarium were incubated for 16 days at 25°C, fixed in OsO₄ vapor at room temperature, dehydrated in a graded ethanol series and stored in 100% ethanol. Fixed specimens were coated with gold and examined with a Stereoscan electron microscope. Initial observations revealed numerous sclerotia and non-spore producing acervuli. After 16 days acervuli in various stages of development were observed. Initial development consisted of periderm swellings caused by a sclerotial body which enlarged to occupy an entire cork cell and eventually ruptured the periderm. A palisade layer formed from which setae developed, and apical ends of conidiophores were evident. Further development of the palisade layer was partially obscured by extrusion of a mucilaginous layer. Cylindrical, single-celled conidia (2.2–3.8u x 14.4–19u) were extruded through the mucilaginous matrix. Remnants of periderm wall were associated with acervuli and conidia lay in closely packed masses around the bases of mature acervuli. Conidia washed from spore producing acervuli onto PDA, germinated within 24 hours at room temperature. Electron scan is a rapid method for following acervulus development ofC. atramentarium on diseased potato periderm and demonstrates the feasibility of studying other potato periderm diseases with this technique.     

Pectic enzyme production by two strains of pseudomonas fluorescens associated with the pinkeye disease of potato tubers

A bacterium identified asPseudomonas fluorescens was isolated from pinkeye lesions of infected Kennebec potato tubers. Two isolates which rapidly macerated tuber slices were selected for further study. Supernatants from macerated potato tuber slices inoculated previously with either isolate 13 or 31 ofP. fluorescens contained pectic enzyme activity. Trace amounts of pectin methylesterase activity were observed in the supernatants. Optimum viscosity reduction of sodium polypectate (NaPP) or pectin substrates by the enzyme complexes occurred at pH 8.6 and 7.2 respectively. Paper chromatography of hydrolysis products indicated that substrates were hydrolyzed terminally as well as randomly when the reaction mixtures were buffered from pH 7.1 to 7.5 NaPP was degraded more rapidly than pectin by both enzyme complexes. Reducing group data indicated the greatest hydrolysis of both substrates occurred near pH 8.6 and that both enzyme complexes hydrolyzed NaPP preferentially. Trans-eliminase activity was found in both enzyme complexes. Optimum activity occurred between pH 8.0 and 9.0 using a NaPP substrate and between pH 7.0 and 8.0 using pectin. The addition of calcium to the reaction mixture increased hydrolysis suggesting the importance of calcium as a co-factor for trans-eliminase activity. Both enzyme complexes macerated potato tuber slices rapidly. Data suggested a relationship between viscosity reduction of NaPP, transelimination of NaPP, and loss of coherence of tuber tissue slices by enzyme complexes of both isolates.