Interhemispheric correlation of late pleistocene glacial events

A radiocarbon chronology shows that piedmont glacier lobes in the Chilean Andes achieved maxima during the last glaciation at 13,900 to 14,890, 21,000, 23,060, 26,940, 29,600, and >/=33,500 carbon-14 years before present ((14)C yr B.P.) in a cold and wet Subantarctic Parkland environment. The last glaciation ended with massive collapse of ice lobes close to 14,000(14)C yr B.P., accompanied by an influx of North Patagonian Rain Forest species. In the Southern Alps of New Zealand, additional glacial maxima are registered at 17,720(14)C yr B.P., and at the beginning of the Younger Dryas at 11,050 (14)C yr B. P. These glacial maxima in mid-latitude mountains rimming the South Pacific were coeval with ice-rafting pulses in the North Atlantic Ocean. Furthermore, the last termination began suddenly and simultaneously in both polar hemispheres before the resumption of the modern mode of deep-water production in the Nordic Seas. Such interhemispheric coupling implies a global atmospheric signal rather than regional climatic changes caused by North Atlantic thermohaline switches or Laurentide ice surges.     

Complement factor H variant increases the risk of age-related macular degeneration

Age-related macular degeneration (AMD) is a leading cause of visual impairment and blindness in the elderly whose etiology remains largely unknown. Previous studies identified chromosome 1q32 as harboring a susceptibility locus for AMD. We used single-nucleotide polymorphisms to interrogate this region and identified a strongly associated haplotype in two independent data sets. DNA resequencing of the complement factor H gene within this haplotype revealed a common coding variant, Y402H, that significantly increases the risk for AMD with odds ratios between 2.45 and 5.57. This common variant likely explains approximately 43% of AMD in older adults.     

Black leaf streak disease and plantain fruit characteristics as affected by tree density and biomass management in a tropical agroforestry system

Black leaf streak disease (BLSD) affects both bananas and plantains. Anecdotal evidence suggests that when plantain is grown under shade in agroforestry systems, there is less damage from BLSD. In this study, BLSD severity and agronomic fruit characteristics of plantain were compared under high and low timber stand densities (TSD), and also under different crop management systems (mulching, burning, intercropping). By 11 months after planting, in high TSDs, plants had 1.2 more standing leaves, 1.5 more symptom-free leaves and a lower percentage of total leaf area attacked than in low TSDs. At harvest, plants in high TSDs had, on average, 1.4 more standing leaves than those in low TSDs. Percentage leaf area attacked by BLSD was 43.0 % in high TSD treatments, significantly lower than the 57.2 % in low TSD treatments. There was a significant and positive relationship between the number of leaves at flowering and dry fruit bunch mass for plantains grown under low TSD. However, there was no correlation between the number of leaves and fruit mass for the high TSD. The beneficial effects of shade in the high TSD, such as reduced severity of BLSD, were established. However, as there was bunch mass loss associated with reduced leaf production rates under the high TSD, a reduction in BLSD only partially compensated for this yield loss. Thus overall, at the high TSD, there was no yield gain from reduced BLSD.     

Evaluation of effectiveness and efficiency of wild bird surveillance for avian influenza

This study aimed to assess which method of wild waterbird surveillance had the greatest probability of detecting highly pathogenic avian influenza (HPAI) H5N1 during a period of surveillance activity, the cost of each method was also considered. Lake Constance is a major wintering centre for migratory waterbirds and in 2006 it was the site of an HPAI H5N1 epidemic in wild birds. Avian influenza surveillance was conducted using harmonised approaches in the three countries around the lake, Austria, Germany and Switzerland, from 2006–2009. The surveillance consisted of testing birds sampled by the following methods: live birds caught in traps, birds killed by hunters, birds caught in fishing nets, dead birds found by the public and catching live Mute Swans (Cygnus olor); sentinel flocks of Mallards (Anas platyrhynchos) were also used. Scenario tree analysis was performed including sensitivity analysis, followed by assessment of cost-effectiveness. Results indicated that if HPAI H5N1 was present at 1% prevalence and assuming HPAI resulted in bird mortality, sampling dead birds found by the public and sentinel surveillance were the most sensitive approaches despite residual uncertainty over some parameters. The uncertainty over the mortality of infected birds was an influential factor. Sampling birds found dead was most cost-effective, but strongly dependent on mortality and awareness of the public. Trapping live birds was least cost-effective. Based on our results, we recommend that future HPAI H5N1 surveillance around Lake Constance should prioritise sentinel surveillance and, if high mortality is expected, the testing of birds found dead.     

Variants of somatotropin in cattle: gene frequencies in major dairy breeds and associated milk production

The amino acid sequence of bovine somatotropin (bST) varies at position 127 where either valine or leucine is found. The frequencies of leucine₁₂₇ and valine₁₂₇ bST gene alleles in cows (n = 302) and sires (n = 70) from major dairy breeds (Holstein, Brown Swiss, Guernsey, Jersey, and Ayrshire) were determined using DNA extracted from whole blood or spermatozoa. A 428 base pair fragment of the bST gene was amplified using polymerase chain reaction (PCR) and variants of the bST gene were detected as polymorphisms by Alu I restriction endonuclease digestion of PCR products. Restriction enzyme DNA fragments for the leucine₁₂₇ variant were 265, 96, 51, and 16 base pair and for the valine₁₂₇ variant were 265, 147, and 16 base pair as a polymorphism of bST was present in the 147 base pair DNA fragment. Frequencies of leucine₁₂₇ and valine₁₂₇ alleles for cows (n=302) were 1.0 and 0 for Brown Swiss, .93 and .07 for Holstein, .92 and .08 for Guernsey, .79 and .21 for Ayrshire, and .56 and .44 for Jersey, respectively. In Holstein sires used for artificial insemination (n=70), the frequency of leucine₁₂₇ and valine₁₂₇ alleles was .96 and .04. Estimates of transmitting ability for milk production tended to be greater for Holstein cows that were homozygous for leucine₁₂₇ bST and Jersey cows that were homozygous for valine₁₂₇ bST whereas Holstein sires with different bST genotypes were similar. In summary, frequencies of alleles for the bST gene were not similar in different dairy breeds and estimates of milk production were correlated with bST gene variant in cows but not sires.     

Stochastic modelling as a tool for planning animal-health surveys and interpreting screening-test results

Traditionally, the planning of surveys (in particular, sample-size calculations) has relied on assumptions including the assumption of perfect screening tests. This paper presents a novel approach that can be used for planning animal-health surveys and interpreting screening-test results in the context of these surveys. A stochastic simulation model developed to assess the properties of herd-level sampling schemes and surveys has been adapted for large surveys aimed at substantiating freedom from infection at a national or regional level. We use a Bayesian approach to derive the post-survey probability of freedom from infection from the pre-survey probability of freedom and the likelihood ratio that is associated with screening-test results. We applied the model to two consecutive surveys conducted in 1998 and 1999 in Switzerland to substantiate freedom from infectious bovine rhinotracheitis (IBR) in the cattle population of about 56000 herds (median herd size of 15 cattle > 2 yr of age in 1999). In 1998, serum samples were taken from five cattle > 2 yr in 4672 herds, and in 1999 from all cattle > 2 yr old in 648 herds; samples were analysed by ELISA. The survey of 1999 provided less evidence than that of 1998 to support a status of freedom from infection; also, the characteristics of both herd-level sampling schemes were similar. We argue that the rationale for survey planning depends on the pre-survey probability of freedom from infection (i.e. our level of confidence that the infection does not occur in the targeted animal population). In consequence, surveys should be tailored to individual populations in the respective countries or regions. The model has been developed in an Excel spreadsheet to allow flexibility of use, and adaptation to many other animal-health issues.     

Myxosarcoma in the eye and brain in a dog

A male mixed breed dog of unknown age was presented with sudden onset of blindness and a slightly exophthalmic right eye. Ophthalmoscopically, a spherical, pinkish mass protruding from the region of the optic disc into the vitreous was seen in the right eye. Ultrasound and computer tomography demonstrated an extension of the mass into the right retrobulbar space, continuing intracranially to the optic chiasm. Cytologic findings, obtained by ultrasound-guided fine needle aspiration from the retrobulbar space, were consistent with myxosarcoma. On the basis of these findings of a well-delineated mass in the brain stem area, irradiation was planned as the therapy of choice. The dog was treated under general anesthesia using a proton beam at the Paul Scherrer Institute (PSI, Villigen, Switzerland). A curative protocol (56 Gy in 16 fractions over 4 weeks, 3.5 Gy/fraction) was used. Twenty-seven days post radiation therapy the dog was euthanized, as clinical symptoms progressed. Enlargement of the intracranial tumor was seen on a CT study repeated on the day of euthanasia. A gross pathologic and histologic examination were performed and confirmed the diagnosis of a myxosarcoma involving the eye, retrobulbar space of the right side, and the optic chiasm. Post-mortem examination failed to identify any abnormalities or metastases elsewhere in the body.