Influence of Nutrients in Water and Sediments on the Spatial Distributions of Benthos in Lake Simcoe

The shoreline and sublittoral areas of Lake Simcoe were surveyed in October 2005 as part of a baseline inventory of current conditions, and as part of an exploratory analysis to determine if there were threshold nutrient levels above which nutrients were a major controlling factor in the distributions (abundances) of benthic organisms. Along the shore environment, there was no generalized relationship between nutrients and indices of benthic community composition below water-borne total phosphorus concentrations of ∼ 0.05 mg/L, indicating that other factors were more important at those lower levels of phosphorus. Benthic community composition did not vary with water quality in the sublittoral zone, but did vary with sediment quality (total Kjeldahl nitrogen, total phosphorus). The benthic community had higher relative abundances of caddisflies and mayflies at sublittoral stations with TKN levels at or near the provincial low-effect level of 550 mg/kg, and had higher relative abundances of more tolerant taxa such as worms, amphipods, and snails at locations with TKN levels in excess of the provincial severe-effect level of 4,800 mg/kg. The relationship between composition and TKN in sediments was not obvious below concentrations of ∼ 300 mg/kg, indicating that other factors were more important at those levels of TKN. This study was the first to document an inland (non-Great Lake) colonization by the exotic amphipod Echinogammarus ischnus. This species was found along most of the shoreline with the exception of shorelines within Cook's Bay, along Sibbald Point Provincial Park and at the far end of Kempenfelt Bay. Where found, E. ischnus were generally numerically dominant members of the benthic community.     

Pyrogenic inputs of anthropogenic Pb and Hg to sediments of the Hood Canal, Washington, in the 20th century: source evidence from stable Pb isotopes and PAH signatures

Combustion-derived PAHs and stable Pb isotopic signatures ((206)Pb/(207)Pb) in sedimentary records assisted in reconstructing the sources of atmospheric inputs of anthropogenic Pb and Hg to the Hood Canal, Washington. The sediment-focusing corrected peak fluxes of total Pb and Hg (1960-70s) demonstrate that the watershed of Hood Canal has received greater atmospheric inputs of these metals than its mostly rural land use would predict. The tight relationships between the Pb, Hg, and organic markers in the cores indicate that these metals are derived from industrial combustion emissions. Multiple lines of evidence point to the Asarco smelter, located in the Main Basin of Puget Sound, as the major emission source of these metals to the watershed of the Hood Canal. The evidence includes (1) similar PAH isomer ratios in sediment cores from the two basins, (2) the correlations between Pb, Hg, and Cu in sediments and previously studied environmental samples including particulate matter emitted from the Asarco smelter's main stack at the peak of production, and (3) Pb isotope ratios. The natural rate of recovery in Hood Canal since the 1970s, back to preindustrial metal concentrations, was linear and contrasts with recovery rates reported for the Main Basin which slowed post late 1980s.     

Analysis of the causality links between the growth of the construction industry and the growth of the macro‐economy in Ghana

A vibrant construction industry in a developing country, that mobilizes human and local material resources in the development and maintenance of buildings, housing and physical infrastructure, is an important means to promote increased local employment and accelerate economic growth. Ghana, a country of about 22 million people, currently has one of the fastest growing economies in West Africa. The Government of Ghana (GOG) has recently set a target of annual economic growth rate of 8% and above, up from annual growth rates of 5–6% in the past five years (2001–05). It intends to use the agricultural sector as the major vehicle for achieving such high growth rates in order for the country to reach the status of a middle income country by 2015. Surprisingly, the construction industry was left out from the list of major growth drivers of the economy. We contend that with the construction industry currently making up the third largest sector of the economy, special attention should be given to this industry as one of the main drivers of economic growth in Ghana. Therefore we conducted a study to analyse the causality links between the growth in the construction industry and the growth in the macro‐economy of Ghana, measured by the gross domestic product (GDP), to ascertain whether the construction industry can be used to lead the entire economy on a growth path. The analysis was based on a simple Granger causality test using time series data from 1968 to 2004. We showed that growth in the construction industry Granger‐caused growth in GDP, with a three‐year lag. The construction industry needs to be considered as one of the major drivers of economic growth in Ghana.     

“Neutron Shell”: a high efficiency array of neutron detectors for γ-ray spectroscopic studies with Gammasphere

A shell of neutron detectors was designed, constructed, and employed in γ-ray spectroscopy with Gammasphere. It consists of up to 35 tapered regular hexagons that replace the same number of forward Ge-detector modules in Gammasphere. The shell was designed for high detection efficiency and very good neutron–γ discrimination. The simultaneous use of time-of-flight, and two methods of pulse shape discrimination between neutrons and γ rays is described. Techniques for spectroscopy with efficient detection of two neutrons are discussed.     

Development of an Australian Bread Wheat Nested Association Mapping Population,A New Genetic Diversity Resource for Breeding under Dry and Hot Climates

Genetic diversity, knowledge of the genetic architecture of the traits of interest and efficient means of transferring the desired genetic diversity into the relevant genetic background are prerequisites for plant breeding. Exotic germplasm is a rich source of genetic diversity; however, they harbor undesirable traits that limit their suitability for modern agriculture. Nested association mapping (NAM) populations are valuable genetic resources that enable incorporation of genetic diversity, dissection of complex traits and providing germplasm to breeding programs. We developed the OzNAM by crossing and backcrossing 73 diverse exotic parents to two Australian elite varieties Gladius and Scout. The NAM parents were genotyped using the iSelect wheat 90K Infinium SNP array, and the progeny were genotyped using a custom targeted genotyping-by-sequencing assay based on molecular inversion probes designed to target 12,179 SNPs chosen from the iSelect wheat 90K Infinium SNP array of the parents. In total, 3535 BC₁F_4:6 RILs from 125 families with 21 to 76 lines per family were genotyped and we found 4964 polymorphic and multi-allelic haplotype markers that spanned the whole genome. A subset of 530 lines from 28 families were evaluated in multi-environment trials over three years. To demonstrate the utility of the population in QTL mapping, we chose to map QTL for maturity and plant height using the RTM-GWAS approach and we identified novel and known QTL for maturity and plant height.     

Choline Improves Neonatal Hypoxia-Ischemia Induced Changes in Male but Not Female Rats

Choline is an essential nutrient with many roles in brain development and function. Supplementation of choline in early development can have long-lasting benefits. Our experiments aimed to determine the efficacy of choline supplementation in a postnatal day (PND) 10 rat model of neonatal hypoxia ischemia (HI) at term using both male and female rat pups. Choline (100 mg/kg) or saline administration was initiated the day after birth and given daily for 10 or 14 consecutive days. We determined choline’s effects on neurite outgrowth of sex-specific cultured cerebellar granule cells after HI with and without choline. The magnitude of tissue loss in the cerebrum was determined at 72 h after HI and in adult rats. The efficacy of choline supplementation in improving motor ability and learning, tested using eyeblink conditioning, were assessed in young adult male and female rats. Overall, we find that choline improves neurite outgrowth, short-term histological measures and learning ability in males. Surprisingly, choline did not benefit females, and appears to exacerbate HI-induced changes.     

Busy doing quite a lot!

Vertical gastroplasty was applied in surgical treatment of obesity in two patients. There were no complications. During the first year after the operation the patients body mass have reduced by 35-41 kg (25-29% of initial).