Spatial relationships of grassland net ecosystem carbon dioxide exchange in a first-order agricultural basin in southern Ontario

This study quantified the midday (10:00 – 16:00) summer source/sink CO2 relationships of various land-use types, particularly grass-dominated riparian areas, using dynamic chamber techniques, while evaluating the relative contribution of root and microbial components towards the overall soil respiration. The influence of nearby agriculture and was related to elevated N and P, which were 40 and 1000% larger, respectively. A site adjacent to cropped fields showed similar (within 8%) study averaged soil respiration as an open grassland site, but 22% lower soil respiration than a riparian site 250-300 m downstream, which is adjacent to an open grassland fallow. A maple woodlot site exhibited the lowest soil respiration. Patterns were different for vegetative dynamics, such that a grass-dominated riparian site adjacent to agriculture showed 18 to 40% larger ecosystem (soil and vegetation) respiration, 36 and 60% greater net ecosystem CO2 exchange (NEE) and 23 and 45% higher net ecosystem productivity (NEP) than a grass-dominated riparian area adjacent to an open grassland and an open grassland site, respectively. Ambient air (Ta) and soil temperature (Tg) at 5 cm were the best predictors of temporal variability in soil and ecosystem respiration for all grass-dominated sites, whereas Tg was the best predictor of the temporal variability of soil respiration at the maple woodlot site. Volumetric soil moisture content (VSM) also exerted substantial temporal control on soil respiration through a quandratic relationship. Weak temporal relationships between Ta, Tg and VSM, with NEE and NEP, were shown. Spatially, study averaged site ecosystem respiration, NEE and NEP for vegetated plots showed strong positive relationships, close to unity, with the site average total nitrogen, C/N ratio and above-ground biomass. Results showed that grass-dominated riparian and non-riparian areas, with similar vegetation that appear to be homogenous, located approximately 250-300 m from one another, exhibited spatially differing CO2 exchange dynamics based primarily on location within the watershed. In addition, soil and ecosystem dynamics exhibited differing spatial and temporal responses to soil N inputs. This highlights the need to better assess CO2 fluxes from heterogeneous agricultural landscapes. Furthermore, it emphasises that estimates based solely on soil or vegetated surfaces can be rather conservative and may not capture the inherent spatial variability and small scale processes that drive CO2 exchange

"Liquidity, Uncertainty, and the Declining Predictive Power of the Paper-bill Spread"

This paper addresses two questions. First, what causes the paper-bill spread to vary over time in anticipation of income fluctuations’? Second, why has the predictive power of the spread declined in recent years? Consistent with previous empirical work, the paper provides evidence for the default-risk, monetary, and cash-flow hypotheses. Moreover, new evidence is provided for the liquidity hypothesis by showing that uncertainty has a strong impact on the paper-bill spread. This finding holds for two different approaches used to measure uncertainty - financial market volatility and forecaster discord - and for uncertainty about five different variables: the federal funds rate, the Treasury bill rate, the long-term corporate bond rate, stock returns, and industrial production. Using a Kalman filter to recursively estimate the reduced-form model for the paper-bill spread, the paper shows that the impact of monetary policy and uncertainty on the spread declined during the 1980s, while the impact of default risk increased. These findings are explained by two financial market developments occurring during the 1980s: 1) the rapid growth in the volume and liquidity of the commercial paper market, and 2) increased financial fragility of commercial paper issuers.

A critical evaluation of the constitutional protection of fundamental liberties in Malaysia : the meaning of "law" / Sharon K. Chahil

The purpose of this analysis is to evaluate the extent to which the definition of "law" in Articles 5(1), 13(1) and other fundamental liberties provisions of the Federal Constitution provides for the element of natural justice. The importance of this endeavour lies in the fact that in the absence of the element of natural justice, "law" may be utilised to wantonly abrogate the fundamental liberties provisions stipulated in the Federal Constitution

Investigating the Utilization of Research Evidence in the 4-H Youth Development Program

This study investigated the acquisition, interpretation, and utilization of research evidence in the 4-H Youth Development Program from the frame of Social Cognitive Theory. Utilizing Consensual Qualitative Research, we interviewed twenty 4-H faculty, staff, and volunteers from seven states. Results indicated four domains, which covered participants’ definitions of research utilization, their experiences utilizing research, the process of acquiring and distributing research, and barriers and facilitators to research utilization. Participants described research use primarily in terms of improving 4-H programs. They discussed their level of confidence (i.e. self-efficacy) in finding and applying research evidence and their beliefs about the outcomes of research utilization (i.e. outcomes expectancy). Participants mentioned such barriers as not knowing where to look for research, lack of time, lack of funding, and difficulty applying research findings to their work. The facilitators included support from other 4-H colleagues and availability of 4-H specific conferences, publications, and curriculum databases

Screening for eukaryotic signal transduction and Mycobacterium isocitrate lyase inhibitor from actinomycetes and fungi of dipterocarp rain forests at Imabak Valey, Sabah, Malaysia

A diversity of actinomycetes and fungi was isolated from various sites during the Imbak Valley Scientific Expedition 2000. A total of 144 soil samples were collected under trees that have been identified to species or genus level. Imbak Valley is a lowland dipterocarp forest, which is interestingly dominated by Dryobalanops beccarii. Isolation of Streptomyces and non-Streptomyces actinomycetes on HV medium and other specific isolation media for non-Streptomyces yielded 203 isolates from 89 soil samples. Morphological characterisation of the isolated actinomycetes was carried out based on aerial mycelium colour, substrate mycelium colour and diffusible pigment production on oatmeal medium. Nine strains of fungi were isolated from the six soil samples plated on PDA medium. All actinomycetes isolates were grown under aerobic condition in liquid culture and extracted with acetone, and used for screening against proteins involved eukaryotic signal transduction. Yeast MAPK kinase and MAP kinase phosphatase were some of the targeted proteins used in this research. MKK1P386 and MKK1P386-MSG5 mutant yeasts were used to screen for these inhibitors, as these yeast kinase and phosphatase have homologous proteins in the MAP kinase signal transduction pathway in human. No inhibitors in the extracts were found in these screenings. Type 1 protein serine/ threonine phosphatase (GLC7) in yeast was used to screen inhibitors against PP1 inhibitors and no inhibitor was found. None of the fungal extracts showed any inhibitory activities in all the screening systems. No Ras/Raf inhibitor was found in the in vivo Ras/Raf interaction with the yeast two-hybrid screening system, which used to screen for inhibitor against Ras/ Raf protein interaction inhibitor. There were 11 actinomycetes extracts that showed toxicity against yeast strain LZ (transformant of Ras/ Raf). H7667, a Streptomycete toxic to yeast is further screened for inhibitors of the GSK3-beta pathway. H7763, a Streptomyces species that showed positive in the primary screen for inhibitor of isocitrate lyase (ICL) which is not itaconic acid (known ICL inhibitor). H7240 showed the strongest susceptibility towards the resin in which the concentration of 5g/l of resin is sufficient to produce growth inhibition of the bacteria