bluuebunny/crossref_metadata_2025 huggingface dataset:
China's Sovereign Wealth Fund: Weakness and Challenges
Authors: Zhang Ming , He Fan
Published: January 2009

The establishment of sovereign wealth funds in large developing countries has generated hot debate among participants in the international financial market. When accumulated foreign exchange reserves surpass a sufficient and an appropriate level, the costs, risks and impacts of holding reserves on the macroeconomy of a country need to be considered. The Chinese Government established China Investment Corporation (CIC) in 2007 to diversify its investment of foreign reserves and to raise investment income. However, because of certain conflicts of interest and institution‐design caveats, CIC possesses some internal weakness, including a vague orientation, mixed investment strategies and an inefficient bureaucratic style. Although the subprime crisis has softened certain regulations and lessened rejection by the USA of CIC potential investments, the increased volatility and uncertainty of the market means that CIC is facing some new challenges in terms of its investment decisions. Moreover, CIC is competing with other Chinese investment institutions for injections of funds from the Chinese Government.
Active‐Constructive‐Interactive: A Conceptual Framework for Differentiating Learning Activities
Authors: Chi Michelene T. H.
Published: January 2009

Active, constructive, and interactive are terms that are commonly used in the cognitive and learning sciences. They describe activities that can be undertaken by learners. However, the literature is actually not explicit about how these terms can be defined; whether they are distinct; and whether they refer to overt manifestations, learning processes, or learning outcomes. Thus, a framework is provided here that offers a way to differentiate active, constructive, and interactive in terms of observable overt activities and underlying learning processes. The framework generates a testable hypothesis for learning: that interactive activities are most likely to be better than constructive activities, which in turn might be better than active activities, which are better than being passive. Studies from the literature are cited to provide evidence in support of this hypothesis. Moreover, postulating underlying learning processes allows us to interpret evidence in the literature more accurately. Specifying distinct overt activities for active, constructive, and interactive also offers suggestions for how learning activities can be coded and how each kind of activity might be elicited.
Children’s Grammars Grow More Abstract with Age—Evidence from an Automatic Procedure for Identifying the Productive Units of Language
Authors: Borensztajn Gideon , Zuidema Willem , Bod Rens
Published: January 2009

We develop an approach to automatically identify the most probable multiword constructions used in children’s utterances, given syntactically annotated utterances from the Brown corpus of CHILDES. The found constructions cover many interesting linguistic phenomena from the language acquisition literature and show a progression from very concrete toward abstract constructions. We show quantitatively that for all children of the Brown corpus grammatical abstraction, defined as the relative number of variable slots in the productive units of their grammar, increases globally with age.
The Force of Law: Australian Auditing Standards and Their Impact on the Auditing Profession
Authors: Hecimovic Angela , Martinov‐Bennie Nonna , Roebuck Peter
Published: January 2009

This study examines the impact of the introduction of the legally enforceable Australian Auditing Standards (ASAs) on the auditing profession after the first year of implementation. The study compliments and extends the Australian Government's April 2006 pre‐implementation Regulation Impact Statement, which identified potential costs, benefits and other impacts of the new regulatory regime. Relevant data were collected through interviews with the key stakeholders. Overall, the results suggest that the additional burden of compliance with the legally enforceable ASAs has not increased perceived audit quality or public confidence, which were the main aims of the government's regulatory intervention.
Implications of Applying a Private Sector Based Reporting Model to Not‐for‐Profit Entities: The Treatment of Charitable Distributions by Charities in New Zealand
Authors: Van Staden Chris , Heslop James
Published: January 2009

In this paper, we investigate the practical and conceptual difficulties caused by applying a private sector based reporting model to the not‐for‐profit sector. We deal specifically with reporting on charitable distributions by charities in New Zealand. We find a majority of the entities report charitable distributions in the Statement of Financial Performance (as expenses). This approach is conceptually justifiable, complies with international best practice, and is in line with the accountability argument made in this paper. While the number reduced between 2003 and 2007, a significant minority of the entities report charitable distributions in the Statement of Movements in Equity (and therefore report higher surpluses). These two approaches lead to very different results, yet both are apparently seen as acceptable by the entities and their auditors. While this raises questions as to the understandability and comparability of the financial reporting by these entities, it also raises questions about the suitability of the for‐profit sector reporting requirements for the not‐for‐profit sector.
Interpreting the Public Interest: A Survey of Professional Accountants
Authors: Davenport Laura , Dellaportas Steven
Published: January 2009

The accounting profession, like all professions, has a commitment to advance the interests of the general community, as well as those they are contractually bound to serve. Providing services altruistically, at times without compensation, is a salient feature of the public interest ideal. A review of the literature indicates that the profession has abandoned its public interest role so that serving self‐interest now appears to have primacy (

Bédard 2001

;

Canning and O'Dwyer 2001

;

Parker 1994

;

Saravanamuthu 2004

). The aim of this paper is to examine members' interpretation of the public interest ideal and to elicit their perceptions on issues arising from the literature. The results of a survey to members of CPA Australia indicate that members can iterate the formal definition of the public interest, but their application of the public interest in conflict of interest situations is inconsistent with this definition.
A Profile of the Non‐Executive Directors of Australia's Largest Companies
Authors: Cortese Corinne
Published: January 2009

This paper presents a profile of the non‐executive directors of Australia's largest public companies. Using descriptive data, it assesses the extent to which these companies adhere to the requirements set down in the Australian Stock Exchange's ‘Principles of Good Corporate Governance’. In particular, board structure and composition is evaluated, and levels of remuneration and independence among non‐executive directors are assessed. The paper concludes with a discussion of perceived versus actual independence of non‐executive directors and the benefits of having non‐executive directors present on company boards.
Inducing a Magnetic Monopole with Topological Surface States
Authors: Qi Xiao-Liang , Li Rundong , Zang Jiadong , Zhang Shou-Cheng
Published: January 2009

Existence of the magnetic monopole is compatible with the fundamental laws of nature; however, this elusive particle has yet to be detected experimentally. We show theoretically that an electric charge near a topological surface state induces an image magnetic monopole charge due to the topological magneto-electric effect. The magnetic field generated by the image magnetic monopole may be experimentally measured, and the inverse square law of the field dependence can be determined quantitatively. We propose that this effect can be used to experimentally realize a gas of quantum particles carrying fractional statistics, consisting of the bound states of the electric charge and the image magnetic monopole charge.
The CsgA and Lpp Proteins of an
Escherichia coli
O157:H7 Strain Affect HEp-2 Cell Invasion, Motility, and Biofilm Formation
Authors: Uhlich Gaylen A. , Gunther Nereus W. , Bayles Darrell O. , Mosier Derek A.
Published: January 2009

In
Escherichia coli
O157:H7 strain ATCC 43895, a guanine-to-thymine transversion in the
csgD
promoter created strain 43895OR. Strain 43895OR produces an abundant extracellular matrix rich in curli fibers, forms biofilms on solid surfaces, invades cultured epithelial cells, and is more virulent in mice than strain 43895. In this study we compared the formic acid-soluble proteins expressed by strains 43895OR and 43895 using one-dimensional sodium dodecyl sulfate-polyacrylamide gel electrophoresis analysis and identified two differentially expressed proteins. A 17-kDa protein unique to strain 43895OR was identified from matrix-assisted laser desorption ionization-time of flight analysis combined with mass spectrometry (MS) and tandem MS (MS/MS) as the curli subunit encoded by
csgA
. A <10-kDa protein, more highly expressed in strain 43895, was identified as the Lpp lipoprotein. Mutants of strain 43895OR with disruption of
lpp
,
csgA
, or both
lpp
and
csgA
were created and tested for changes in phenotype and function. The results of this study show that both Lpp and CsgA contribute to the observed colony morphology, Congo red binding, motility, and biofilm formation. We also show that both CsgA and Lpp are required by strain 43895OR for the invasion of cultured HEp-2 cells. These studies suggest that in strain 43895OR, the murein lipoprotein Lpp indirectly regulates CsgA expression through the CpxAR system by a posttranscriptional mechanism.
Multiple Mechanisms Contribute to the Robust Rapid Gamma Interferon Response by CD8+T Cells duringListeria monocytogenesInfection
Authors: Bou Ghanem Elsa N. , McElroy Denise S. , D'Orazio Sarah E. F.
Published: January 2009

A subset of CD8+T cells can rapidly secrete gamma interferon (IFN-γ) in an antigen-independent and interleukin-12 (IL-12)- and IL-18-dependent manner within 16 h of infection with the intracellular bacterial pathogenListeria monocytogenes. This rapid IFN-γ response is robust enough to be detected directly ex vivo and is not observed following infection with intracellular bacterial pathogens that remain sequestered within host cell vacuoles. We demonstrate here that three distinct pathways can lead to rapid secretion of IFN-γ by CD8+T cells duringL. monocytogenesinfection: (i) a direct cytokine-inducing activity encoded by the cholesterol-dependent cytolysin (CDC) listeriolysin O (LLO) acts within the infected cell, (ii) the pore-forming activity of LLO promotes cytosolic localization of bacterial products that trigger cytosol-specific signaling pathways, and (iii) the sustained presence of high concentrations of bacterial products can exogenously trigger cytokine production. Although it has been suggested that CDC protein toxins may act as Toll-like receptor 4 (TLR4) agonists to trigger proinflammatory cytokine secretion, we show in this report that TLR4 signaling is not required to induce a maximal rapid IFN-γ response by CD8+T cells. The results presented here indicate that multiple mechanisms contribute to the induction of rapid IFN-γ secretion by CD8+T cells duringListeriainfection and that care must be taken when interpreting the results of in vitro assays, since the contribution of each pathway can vary depending on how the assay is performed.
Caspase-1 Mediates Resistance in Murine Melioidosis
Authors: Breitbach Katrin , Sun Guang Wen , Köhler Jens , Eske Kristin , Wongprompitak Patimaporn , Tan Gladys , Liu Yichun , Gan Yunn-Hwen , Steinmetz Ivo
Published: January 2009

The gram-negative rod
Burkholderia pseudomallei
is the causative agent of melioidosis, a potentially fatal disease which is endemic in tropical and subtropical areas. The bacterium multiplies intracellularly within the cytosol, induces the formation of actin tails, and can spread directly from cell to cell. Recently, it has been shown that
B. pseudomallei
can induce caspase-1-dependent cell death in macrophages. The aim of the present study was to further elucidate the role of caspase-1 during
B. pseudomallei
infection. In vivo experiments with
caspase-1
−/−
mice revealed a high susceptibility to
B. pseudomallei
challenge. This phenotype was associated with a significantly higher bacterial burden 2 days after infection and decreased gamma interferon (IFN-γ) and interleukin-18 cytokine levels 24 h after infection compared to control animals.
caspase-1
−/−
bone marrow-derived macrophages (BMM) exhibited strong caspase-3 expression and reduced cell damage compared to wild-type (WT) cells during early
B. pseudomallei
infection, indicating “classical” apoptosis, whereas WT BMM showed signs of rapid caspase-1-dependent cell death. Moreover, we found that
caspase-1
−/−
BMM had a strongly increased bacterial burden compared to WT cells 3 h after infection under conditions where no difference in cell death could be observed between both cell populations at this time point. We therefore suggest that caspase-1-dependent rapid cell death might contribute to resistance by reducing the intracellular niche for
B. pseudomallei
, but, in addition, caspase-1 might also have a role in controlling intracellular replication of
B. pseudomallei
in macrophages. Moreover, caspase-1-dependent IFN-γ production is likely to contribute to resistance in murine melioidosis.
Trypanosoma cruziPromotes Neuronal and Glial Cell Survival through the Neurotrophic Receptor TrkC
Authors: Weinkauf Craig , PereiraPerrin Mercio
Published: January 2009

Trypanosoma cruzi, the agent of Chagas' disease, promotes neuron survival through receptor tyrosine kinase TrkA and glycosylphosphatidylinositol-anchored glial cell-derived family ligand receptors (GFRα). However, these receptors are expressed by only a subset of neurons and at low levels or not at all in glial cells. Thus,T. cruzimight exploit an additional neurotrophic receptor(s) to maximize host-parasite equilibrium in the nervous system. We show here thatT. cruzibinds TrkC, a neurotrophic receptor expressed by glial cells and many types of neurons, and that the binding is specifically inhibited by neurotrophin-3, the natural TrkC ligand. Coimmunoprecipitation and competition assays show that thetrans-sialidase/parasite-derived neurotrophic factor (PDNF), previously identified as a TrkA ligand, mediates theT. cruzi-TrkC interaction. PDNF promotes TrkC-dependent mitogen-activated protein kinase signaling, neurite outgrowth, and survival of genetically engineered PC12 neuronal cells and glial Schwann cells in a TrkC-dependent manner. Thus, TrkC is a new neurotrophic receptor thatT. cruziengages to promote the survival of neuronal and glial cells. The results raise the possibility thatT. cruzirecognition of TrkC underlies regenerative events in nervous tissues of patients with Chagas' disease.
Immunohistochemical analysis of the oxidative phosphorylation complexes in skeletal muscle from patients with mitochondrial DNA encoded tRNA gene defects
Authors: De Paepe B , Smet J , Lammens M , Seneca S , Martin J-J , De Bleecker J , De Meirleir L , Lissens W , Van Coster R
Published: January 2009

Background:

Mitochondrial diseases display a heterogeneous spectrum of clinical phenotypes and therefore the identification of the underlying gene defect is often a difficult task.

Aims:

To develop an immunohistochemical approach to stain skeletal muscle for the five multi-protein complexes that organise the oxidative phosphorylation (OXPHOS) in order to improve the diagnostic workup of mitochondrial defects.

Methods:

OXPHOS complexes were visualised in skeletal muscle tissue using antibodies directed against different subunits. The staining patterns of patients with heteroplasmic defects in mtDNA tRNA genes were compared with those of normal and disease controls.

Results:

Normal skeletal muscle displayed a checkerboard staining pattern for complexes I to V due to the higher mitochondrial content of slow muscle fibres versus fast fibres. In patients with tRNA defects, a much more heterogeneous staining pattern was observed for complex I (all six patients) and complex IV (4 of 6 patients): a mosaic staining pattern in which individual fibres displayed staining intensities that ranged from strong to negative. Ragged red fibres (RRFs) in patients with MERRF (myoclonic epilepsy and ragged red fibres) were all complex I and IV negative, while in patient with MELAS (mitochondrial myopathy, encephalopathy, lactic acidosis and stroke-like episodes) the majority of RRFs were complex I negative and complex IV positive.

Conclusion:

Immunohistochemical detection of OXPHOS complexes could represent a valuable additional diagnostic tool for the evaluation of mitochondrial cytopathy. The technique helps to detect heteroplasmic mtDNA defects. Staining for complex I in particular was able to identify two tRNA patients that stayed undetected with routine histochemical evaluation.
A simultaneous occurrence of Tolosa–Hunt syndrome and fibrillary glomerulonephritis: a case report
Authors: Gigante A , Giannakakis K , Visentini M , Fiorilli M , Barbano B , Renzulli R , Borghesi F , Cianci R
Published: January 2009

Fibrillary glomerulonephritis (FibGN) is a rare cause of progressive renal dysfunction, often leading to dialysis within a few years. A 60-year-old woman presented with a 2 month history of right-sided retro-orbital pain and recent diplopia. Laboratory testing revealed an altered renal function with increased serum creatinine and mild proteinuria. MRI of the brain revealed the presence of a soft tissue mass on the right cavernous sinus compatible with the diagnosis of Tolosa–Hunt syndrome (THS). Renal biopsy showed a pattern compatible with fibrillary glomerulonephritis. For this reason steroid therapy was initiated at a dose of 1 mg/kg/day and adjusted according to the clinical course. Neurological symptoms regressed shortly after the beginning of therapy and renal function and proteinuria remained stable for the 3 years following the withdrawal of steroid therapy. Percutaneous renal biopsy was again performed and confirmed the previous diagnosis of FibGN in association with other glomerular-lesion-like mesangial widening, thickening of capillary walls and severe arterio-arteriolosclerosis. This case report describes what is believed to first report of the association of FibGN and THS, which both responded to steroid therapy.
Intraosseous schwannoma of rib
Authors: Yang J , Guo Q N , Zhang R , Cai P , Yan X C
Published: January 2009

A case of intraosseous schwannoma of rib is presented. A 22-year-old woman was admitted with paroxysmal thoracic pain, unproductive cough and a hard mass of the thorax. CT scan showed a unilocular osteolystic lesion in the rib. A needle biopsy was performed, and a diagnosis of intraosseous schwannoma was made. The patient underwent a partial excision of rib and the tumour was removed. Macroscopic examination revealed a 4×2×1.5 cm solid lesion with destruction of bone. Microscopically, the tumour showed typical features of schwannoma characterised by Antoni A and Antoni B tissues and Verocay bodies. Immunohistochemically, the tumour was positive for S-100 protein, vimentin, neuron specific enolase (NSE) and glial fibrillary acidic protein (GFAP). The patient is well without local recurrence or metastasis after a 1-year follow-up. This is believed to be the second case report of primary schwannoma of rib.
Healthcare professionals’ and researchers’ understanding of cancer genetics activities: a qualitative interview study: Table 1
Authors: Hallowell N , Cooke S , Crawford G , Parker M , Lucassen A
Published: January 2009

Aims:

To describe individuals’ perceptions of the activities that take place within the cancer genetics clinic, the relationships between these activities and how these relationships are sustained.

Design:

Qualitative interview study.

Participants:

Forty individuals involved in carrying out cancer genetics research in either a clinical (n = 28) or research-only (n = 12) capacity in the UK.

Findings:

Interviewees perceive research and clinical practice in the subspecialty of cancer genetics as interdependent. The boundary between research and clinical practice is described as vague or blurred, and this ambiguity is regarded as being sustained by a range of methodological, ethical and economic factors. The implications of these findings for the “therapeutic misconception” are explored. It is argued that while research participation is seen as having therapeutic benefit for individual patients, the interviewees are not labouring under any misconceptions about the relationship between research and clinical care. It is suggested that concepts such as the “therapeutic misconception” may have less relevance in highly technological specialities that are characterised by a developing evidence base.
Broadening consent—and diluting ethics?: Table 1
Authors: Hofmann B
Published: January 2009

Biobank research is potentially fruitful. It is argued that broad consent is acceptable for future research on biological material because a) the benefit is high, b) it pays respect to people’s autonomy, c) it is consistent with current practices and d) because the risk is low. Furthermore, broad consent should be allowed if information is handled safely, people can withdraw and expanded research should be approved by an ethics review board. However, these arguments are flawed and the criteria for broad consent are either too restrictive to allow any research or fail to address important challenges with biobank research. Broad consent for biobank research can hide substantial ethical challenges and threaten trust in research. This does not mean that biobank research should be abandoned or that people cannot authorise future research on donated biological material.
Review of policies for injuries to research participants in India
Authors: Thatte U M , Kulkarni-Munshi R , Kalekar S A
Published: January 2009

Background:

As there is little Indian data about severity, frequency and types of research related injuries, costs involved and policies regarding compensation, this study was conducted to review the present Indian scenario.

Methods:

The study was carried out in three parts; a questionnaire-based survey, in-depth interviews, and a review of informed consent and insurance documents of projects submitted to three ethics committees.

Results:

47% of investigators were either unaware of, or had not understood, the legal requirements and depended on sponsors to manage these issues, whereas 74% of ethics committee members were aware of the requirements. Although 40% of investigators, 30% of ethics committee members and all sponsors had policies to manage compensation issues, these were mainly to provide immediate free medical care or reimbursement of expenses incurred for the acute management of an adverse event. Compensation for loss of time/wages, death, physical disability or long term incapacitation was not included. A review of informed consent and insurance documents showed that compensation issues were inadequately discussed, with only insurance certificates submitted to ethics committees.

Conclusion:

In India, there are no uniform policies and investigators are largely unaware of their responsibilities. Therefore, there is an urgent need to draft national guidelines regarding compensation for research injuries of research participants and highlight the responsibilities of each stakeholder. Potential research injuries should be categorised based on risk assessment, severity and seriousness of the injury. Further, it would be necessary to have arbitration committees to determine the extent of compensation. Training and awareness workshops for those involved in clinical research, including research participants, is also needed.
Seroxat and the suppression of clinical trial data: regulatory failure and the uses of legal ambiguity
Authors: McGoey L , Jackson E
Published: January 2009

This article critically evaluates the Medicines and Healthcare products Regulatory Agency’s announcement, in March 2008, that GlaxoSmithKline would not face prosecution for deliberately withholding trial data, which revealed not only that Seroxat was ineffective at treating childhood depression but also that it increased the risk of suicidal behaviour in this patient group. The decision not to prosecute followed a four and a half year investigation and was taken on the grounds that the law at the relevant time was insufficiently clear. This article assesses the existence of significant gaps in the duty of candour which had been assumed to exist between drugs companies and the regulator, and reflects upon what this episode tells us about the robustness, or otherwise, of the UK’s regulation of medicines.
Predicting the future prevalence of cigarette smoking in Australia: how low can we go and by when?
Authors: Gartner C E , Barendregt J J , Hall W D
Published: January 2009

Background:

In Australia, smoking prevalence has declined in men since the 1950s and in women since the 1980s. Future smoking prevalence in Australia is predicted from estimates of previous and current age-specific and sex-specific cessation rates and smoking uptake in young people derived from national survey data on the prevalence of smoking between 1980 and 2007.

Methods:

A dynamic forecasting model was used to estimate future smoking prevalence in the Australian population based on a continuation of these current trends in smoking uptake and cessation.

Results:

The results suggest that Australia’s smoking prevalence will continue to fall while current rates of initiation and cessation are maintained. But a continuation of current smoking cessation and initiation patterns will see around 14% of adults still smoking in 2020.

Conclusions:

Smoking cessation rates will need to double for Australian smoking prevalence to reach a policy target of 10% by 2020.
Determining the post-glacial evolution of a northeast Pacific coastal fjord using a multiproxy geochemical approachThis article is one of a series of papers published in this Special Issue on the theme Polar Climate Stability Network.
Authors: Ivanochko Tara S. , Calvert Stephen E. , Southon John R. , Enkin Randolph J. , Baker Judith , Dallimore Audrey , Pedersen Thomas F.
Published: January 2009

A 40.32 m piston core recovered from Effingham Inlet, on the west coast of Vancouver Island, provides the basis for a high-resolution geochemical study of the last deglaciation and the Holocene. Glacial retreat, basin isolation, sea-level rise, and productivity variations are determined using proxies for sediment composition (K/Al, Fe/Al, Mg/Al), grain size (Ti/Al, Zr/Al), sedimentary redox conditions (Mo/Al, U/Al), and productivity (wt.% organic carbon, wt.% opal). As local ice retreated and marine waters inundated the basin, coarse-grained glacimarine sediments were replaced by finer grained, laminated, opal-rich sediments. During meltwater pulse-1a, the dominance of local crustal rise over eustatic sea-level rise resulted in the progressive restriction of ocean circulation in Effingham Inlet and the formation of a temporary freshwater lake. The transition into stable Holocene conditions was initiated at ∼12 700 BP, which corresponds to the onset of the Younger Dryas, as identified by the Greenland Ice core Project (GRIP) ice core δ18O record and was completed by 10 700 BP, ∼800 years after the GRIP ice core record stabilized. Holocene Mo/Al and U/Al ratios range between 12–35 (×104) and 1–3.4 (×104), respectively, indicating that although large-amplitude, high-frequency fluctuations occur, the sediments of Effingham Inlet inner basin have remained organic rich and oxygen depleted for the entire Holocene period. The combination of anoxic bottom waters and a Holocene sedimentation rate of 217 cm/ka have preserved a high-resolution record of environmental change in the northeast Pacific over the last 11 000 years.
Impact of melting of the Laurentide Ice Sheet on sediments from the upper continental slope off southeastern Canada: evidence from Sm–Nd isotopesThis article is one of a series of papers published in this Special Issue on the themePolar Climate Stability Network.
Authors: Stevenson R. K. , Meng X. W. , Hillaire-Marcel C.
Published: January 2009

We present new Sm–Nd isotope data for sediments from a core located on the continental slope of the St. Pierre Bank of Canada’s east coast. The Nd analyses indicate that the sediments were derived from two principal sources: the North American Shield that yields an average early Proterozoic isotopic signature and a younger Proterozoic signature attributed to Appalachian crustal sources. The Appalachian-sourced sediments predominated during the last glacial maximum (LGM) and were associated with low sedimentation rates (<30 cm/ka), with the exception of a strong North American Shield signature present in a detrital carbonate layer that corresponds to Heinrich Layer 1 (H1). The dominance of the Appalachian signature decreased subsequent to H1. The Appalachian signatures closely follow the distribution of sediments interpreted as locally derived glacial tills, while the North American Shield signatures follow the distribution of hemipelagic mud that was likely deposited by the Labrador Current. The Nd data are consistent with the persistence of the Wisconsinan Ice Sheet coverage of Newfoundland and the Grand Banks after the LGM, although the coverage began to wane prior to 12.5 ka as evidenced by the increasing influence of the Labrador Current. However, an increase in the Appalachian isotope signature at the close of the Younger Dryas event likely indicates the final melting of the ice sheet covering the Grand Banks and the Avalon Peninsula, and the initiation of the Labrador Current’s modern circulation pathway.
Low- and high-frequency climate variability in eastern Beringia during the past 25 000 yearsThis article is one of a series of papers published in this Special Issue on the theme Polar Climate Stability Network.
Authors: Viau A. E. , Gajewski K. , Sawada M. C. , Bunbury J.
Published: January 2009

We present new temperature and precipitation reconstructions for the past 25 000 cal. years BP from across eastern Beringia based on a network of pollen diagrams, an updated modern pollen calibration database, and an improved methodology using the modern analogue technique (MAT). Time series show July temperatures were around 4 °C lower during full glacial and January temperatures were about 2 °C lower than present. Annual temperatures rose beginning around 16 000 cal. years BP, reaching a maximum around 12 000 cal. year BP. The warming was more rapid in southern Beringia. Annual precipitation varied by 250 mm during the past 25 000 cal. years BP. Maps of reconstructed precipitation patterns show increasingly drier conditions since 12 000 cal. years BP. that vary regionally, suggesting Holocene atmospheric circulation changes at multiple time and space scales. Orbitally forced seasonality changes during the late glacial and early Holocene resulted in reversed seasonal temperature reconstructions due to methodological constraints using the MAT and (or) non-analogue conditions. The magnitude of millennial-scale climate variability in this region was greater during the last glacial and late glacial periods than during the past 8000 years.
Postglacial evolution of a Pacific coastal fjord in British Columbia, Canada: interactions of sea-level change, crustal response, and environmental fluctuations — results from MONA core MD02-2494This article is one of a series of papers published in this Special Issue on the theme Polar Climate Stability Network.
Authors: Dallimore Audrey , Enkin Randolph J. , Pienitz Reinhard , Southon John R. , Baker Judith , Wright Cynthia A. , Pedersen Tom F. , Calvert Steve E. , Ivanochko Tara , Thomson Richard E.
Published: January 2009

The sedimentary record in a 40.9 m giant (Calypso) piston core (MD02-2494) raised from the inner basin within Effingham Inlet, British Columbia, Canada, during the 2002 Marges Ouest Nord Américaines (MONA) campaign, spans from 14 360 14C years BP (17 300 calibrated calendar (cal.) years BP) to about nine centuries before present. The core archives changes in sedimentation and sea level immediately following deglaciation of the Late Wisconsin Fraser Glaciation, which peaked about 15 000 14C years BP. The presence of the Mazama Ash in the core anchors a detailed chronology based on 49 radiocarbon dates and seven Pleistocene paleomagnetic secular variation correlations. Diatom assemblages identify a marine–freshwater–marine transition in the basin, which occurred 11 630 14C years BP (13 500 cal. years BP). At this time, a bedrock sill, presently at 46 m depth, was briefly exposed as sea level fell and then rose again during isostatic crustal adjustments. These data constrain a new sea-level curve for the outer coast of Vancouver Island covering the past 12 000 14C years BP (14 000 cal. years BP), providing new information on the nature of deglaciation along the west coast of Canada and informing interpretations of regional paleoceanographic records and mantle viscosity models.
Palynological evidence of Holocene climate change in the eastern Arctic: a possible shift in the Arctic oscillation at the millennial time scaleThis article is one of a series of papers published in this Special Issue on the theme Polar Climate Stability Network.
Authors: Ledu David , Rochon André , de Vernal Anne , St-Onge Guillaume
Published: January 2009

Dinocyst assemblages and the physical properties of two sediment cores collected in the easternmost part of the main axis of the Northwest Passage, Canadian Arctic Ocean (cores 2004-804-009 BC and 2004-804-009 PC, 74°11.2′N, 81°11.7′W) were used to reconstruct changes in sea-surface conditions and to characterize changes in the depositional environment. Core 2004-804-009 PC spans the last 12 180 calibrated (cal) years BP, with sedimentation rates ranging from 45 to 122 cm/ka. Quantitative estimates of sea-surface parameters reveal relatively large hydrographic variability at millennial time scale. Before 11 000 cal years BP, our records suggest terrigenous inputs related to the last deglaciation. Between 11 000 and 9600 cal years BP, harsh conditions prevailed with August sea-surface temperatures <2 °C and the dominance of heterotrophic taxa. This episode was followed by a gradual increase in the relative abundance of phototrophic taxa and the establishment of milder condition with sea-surface temperature (SST) reaching ∼2 °C ∼8300 cal years BP, possibly related to increased exchange between the Arctic Ocean and the North Atlantic Ocean. From 6000 cal years BP to the late Holocene, climate variability could be the results of changes in the synoptic-scale atmospheric pattern such as the Arctic oscillation.
Holocene fluctuations in Arctic sea-ice cover: dinocyst-based reconstructions for the eastern Chukchi SeaThis article is one of a series of papers published in this Special Issue on the theme Polar Climate Stability Network.GEOTOP Publication 2008-0023.
Authors: McKay J. L. , de Vernal A. , Hillaire-Marcel C. , Not C. , Polyak L. , Darby D.
Published: January 2009

Cores from site HLY0501-05 on the Alaskan margin in the eastern Chukchi Sea were analyzed for their geochemical (organic carbon, δ13Corg, Corg/N, and CaCO3) and palynological (dinocyst, pollen, and spores) content to document oceanographic changes during the Holocene. The chronology of the cores was established from 210Pb dating of near-surface sediments and 14C dating of bivalve shells. The sediments span the last 9000 years, possibly more, but with a gap between the base of the trigger core and top of the piston core. Sedimentation rates are very high (∼156 cm/ka), allowing analyses with a decadal to centennial resolution. The data suggest a shift from a dominantly terrigenous to marine input from the early to late Holocene. Dinocyst assemblages are characterized by relatively high concentrations (600–7200 cysts/cm3) and high species diversity, allowing the use of the modern analogue technique for the reconstruction of sea-ice cover, summer temperature, and salinity. Results indicate a decrease in sea-ice cover and a corresponding, albeit much smaller, increase in summer sea-surface temperature over the past 9000 years. Superimposed on these long-term trends are millennial-scale fluctuations characterized by periods of low sea-ice and high sea-surface temperature and salinity that appear quasi-cyclic with a frequency of about one every 2500–3000 years. The results of this study clearly show that sea-ice cover in the western Arctic Ocean has varied throughout the Holocene. More importantly, there have been times when sea-ice cover was less extensive than at the end of the 20th century.
Holocene and Last Interglacial cloudiness in eastern Baffin Island, Arctic CanadaThis article is one of a series of papers published in this Special Issue on the themePolar Climate Stability Network.GEOTOP Publication 2008-0027.
Authors: Fréchette Bianca , de Vernal Anne , Richard Pierre J.H.
Published: January 2009

This study presents Last Interglacial and Holocene vegetation and climate changes at Fog Lake (67°11′N, 63°15′W) on eastern Baffin Island, Arctic Canada. The vegetation cover is reported as vegetation structural types (or biomes). July air temperature and sunshine during the growing season (June–July–August–September) were reconstructed from pollen assemblages using the modern analogue technique. The vegetation of the Last Interglacial period evolved from a prostrate dwarf-shrub tundra to a low- and high-shrub tundra vegetation. The succession of four Arctic biomes was distinguished from the Last Interglacial sediments, whereas only one Arctic biome was recorded in the Holocene sediments. From ca. 8300 cal. years BP to present, hemiprostrate dwarf-shrub tundra occupied the soils around Fog Lake. During the Last Interglacial, growing season sunshine was higher than during the Holocene and July air temperature was 4 to 5 °C warmer than present. A principal component analysis helped in assessing relationship between floristic gradients and climate. The major vegetation changes through the Last Interglacial and Holocene were driven by July air temperature variations, whereas the minor, or subtle, vegetation changes seem rather correlated to September sunshine. This study demonstrates that growing season sunshine conditions can be reconstructed from Arctic pollen assemblages, thus providing information on feedbacks associated with cloud cover and summer temperatures, and therefore growing season length.
Late Quaternary paleoceanography and paleo-sea ice conditions in the Mackenzie Trough and Canyon, Beaufort SeaThis article is one of a series of papers published in this Special Issue on the theme Polar Climate Stability Network.
Authors: Schell Trecia M. , Scott David B. , Rochon André , Blasco Steve
Published: January 2009

The Mackenzie Trough provides a high resolution signal for paleoceanography as a result of high sedimentation rates at the mouth of the Mackenzie River. Three cores were collected along a transect covering a depth range of 58–671 m and the time period of the last 11 500 cal BP. Prior to the last ∼10 000 cal BP, the distal core is characterized by laminated sediment and a foraminiferal fauna of Arctic Bottom Water calcareous species and abundant planktic foraminifera suggesting little freshwater runoff and (or) perennial sea-ice cover. This occurs at a similar time as laminated sediments from the west of this site, which have been suggested to be part of the Lake Agassiz flood outburst and (or) cold period. If this outburst occurred, the very positive oxygen isotope values from our core (PC3; >+3.0 ppm) indicate that it did not flow through the Mackenzie Trough. After 9000 cal BP, the faunas in the three cores differ because of timing and different water depths. However, it is possible to see a progression of cold saline water prior to 10 000 cal BP, with a freshening of surface water after 10 000 cal BP where tintinnids (brackish water ciliates) occur with incursions of deep water Arctic calcareous species to ∼3000 years BP. A sequence of mixed faunas appears as sea ice returns, at least periodically in the last 3000 cal BP; but (in core PC2 only) a return to more sea ice is recorded by both foraminifera and dinocysts in the last few hundred years.
Last glacial maximum (LGM) primary productivity in the northern North Atlantic OceanThis article is one of a series of papers published in this Special Issue on the theme Polar Climate Stability Network.
Authors: Radi Taoufik , de Vernal Anne
Published: January 2009

To reconstruct oceanic primary productivity in the northern North Atlantic Ocean during the last glacial maximum (LGM), we have applied the modern analogue technique to dinocyst assemblages using a Northern Hemisphere database that includes 1171 reference sites. The reconstructions were made in LGM sediments (21 ± 2 ka) of a set of 62 cores collected from 36°N to 75°N. Here, we present the compilation of reconstructed seasonal and annual productivity during the LGM. Results show lower mean annual productivity during the LGM than at present in the northern North Atlantic. At most high-latitude locations, LGM productivity has been estimated at <200 gC m–2 a–1, with extremely low values (<100 gC m–2 a–1) in the Labrador Sea, Baffin Bay, and along the margins of Greenland. Such low values might be the result of reduced Atlantic Meridional Overturning Circulation and stratified water that characterized the glacial episode of the North Atlantic Ocean.
Solute partitioning in freezing soils
Authors: Konrad J.-M. , McCammon A. W.
Published: January 2009

One-dimensional constant end plate temperature (step freezing) tests were conducted on a saturated clayey silt at various pore-water salinities to establish the relationship between solute rejection and freezing conditions. The rate of cooling, a parameter that is a function of both frost penetration rate and temperature gradient in the frozen soil near the frost front, is the main factor controlling solute partitioning between the solid (ice) and liquid phases. It was also established that there is a threshold rate of cooling of 3 °C/day above which no solutes are rejected from the ice matrix. For rates of cooling smaller than 0.1 °C/day, which incidentally corresponds to most of the field freezing conditions, more than 90% of the solutes are rejected from the pore ice. Key words: freezing, clayey silt, saline, solute, exclusion, rate of cooling.
Mercury intrusion and permeability of Louiseville clay
Authors: Lapierre Clément , Leroueil Serge , Locat Jacques
Published: January 2009

Several theories have been proposed to correlate the permeability (hydraulic conductivity) with the pore-size distribution of soils, and it seemed interesting to determine if these theories could be applied to natural clays. For this purpose permeability and mercury-intrusion porosimetry tests were performed on a Champlain Sea clay for both intact and remoulded conditions after compression of the specimens to strains varying from 0 to 42%. The results show that for either intact or remoulded soil conditions, there is a relationship between the pore-size parameters and the permeability of the clay. However, there is no unique relationship for both intact and remoulded clays and for the silt and clay considered in previous studies. Consequently, mercury-intrusion porosimetry alone cannot be used to evaluate the permeability of soils in general. Key words: permeability, clays, mercury-intrusion porosimetry, fabric.
Influence of polysaccharides on kaolinite structure and properties in la kaolinite–water system
Authors: Yong Raymond N. , Mourato Diana
Published: January 2009

The influence of soil organics on the development of soil structure and behaviour of soils is the motivation for this study. Xanthan and dextran, two soil polysaccharides, were examined in relation to their influence on the development of the structure of kaolinite–polysaccharide systems and also on resultant physicochemical properties. The kaolinite–polysaccharide soils were formed in suspensions under anaerobic and low redox potential conditions to simulate environmental conditions that exist in subsurface soils. Information on the rheology of the kaolinite–polysaccharide system, zeta potential, aggregate size, settling properties, and specific surface area were obtained. Both polysaccharides were shown to develop aggregate groups (floes) which participated to a greater or lesser extent in the overall rheological properties of the kaolinite–polysaccharide complexes. The ability of the polysaccharides to develop flocs is seen as a factor to be considered in studies of soil permeability and transport processes in soil. Together with information from infrared spectroscopy and scanning electron microscopy, and in combination with the results obtained from the physicochemical tests, models of interaction between kaolinite and both polysaccharides are proposed. Key words: soil organics, polysaccharides, kaolinite, rheology, floes, xanthan, dextran, soil structure, zeta potential, kaolinite–polysaccharide system, differential viscosity, Bingham yield stress.
Numerical modelling of toppling
Authors: Pritchard M. A. , Savigny K. W.
Published: January 2009

Evidence of large-scale toppling deformation has been reported in association with deep-seated landslides affecting mountain slopes along the Beaver River valley, Glacier National Park, British Columbia, Canada. A study has been undertaken to quantitatively investigate the relationship between the toppling mass movement process and the deep-seated landslides; specifically, whether the landslides represent a limiting condition of the toppling process. This is the first of two papers that describe the study. Methods of toppling analysis, including limit-equilibrium, finite-element, and distinct-element methods, are critically reviewed. The distinct-element method emerges as the best technique for modelling both block and flexural modes of toppling. The method is verified by modelling three examples of toppling: a theoretical block topple, a physical model of flexural toppling, and an engineered slope from the Brenda mine near Peachland, British Columbia. The results demonstrate that the Universal Distinct Element Code (UDEC) is capable of modelling both block and flexural types of toppling, that the toppling mass movement process limits to deep-seated planar aswell as curvilinear landslides, and that other landforms such as obsequent scarps and grabens are a manifestation of the toppling process. The research reported here contributes to understanding of the deformation behaviour of engineered slopes and the evolution of natural slopes in rock masses containing pervasive discontinuities. Key words: block toppling, flexural toppling, landslide, numerical modelling, distinct element, DDEC, sackung.
The moire crack gauges on the crown of the Frank Slide
Authors: Kostak B. , Cruden D. M.
Published: January 2009

Two TM71 Crack Monitors installed in a gaping crack in the crown of the Frank Slide, Alberta, have recorded movements of less than 1 mm/year. These movements are attributed to continuing dilation of the rock block field in the crown. The crack monitors' moire fringe measurement system is particularly suited to the reliable measurement of small movements over long time periods. Key words: displacements, monitoring, rock, Rockies, creep, interferometry.