bluuebunny/crossref_metadata_2025 huggingface dataset:
Mechanisms of floodbank failure during large flood events on the rivers Tay and Earn, Scotland
Authors: Gilvear D. J. , Davies J. R. , Winterbottom S. J.
Published: November 2007

This paper describes flood embankment breaches on the Tay and Earn river systems, Scotland, during a 100-year return period flood in January 1993. The location of flood embankment breaches are compared with failures mapped during another large flood event in February 1990 and other historical information on flood embankment instability. Breaches were identified using colour aerial photography taken 10 days after the January 1993 flood event and a detailed field survey of every flood embankment breach was subsequently undertaken. In total, 116 breaches resulted from the 1993 flood event, most as a result of overtopping, and extensive floodplain damage was associated with a number of the failures.

Specific sections of the Tay and Earn river systems demonstrated a high incidence of flood embankment breaching. Along these sections, embankments on the outside of bends and overlying old river courses are highly vulnerable to failure. Embankments bordering tributary streams are also vulnerable to failure as a result of being perpendicular to the direction of flow across the floodplain during inundation. A number of failures, however, cannot be attributed directly to their position relative to the river or former river courses. In these cases local factors, such as scour around fence-posts or poor flood embankment construction are probably dominant. Given the repeated breaching of embankments during flood events, changing agricultural land-use practices, and possible changes in flood magnitudes and frequencies, a number of recommendations concerning flood embankment management on the Tay and Earn river systems are proposed.
Jubilee Line Extension
Authors: Page D. P.
Published: November 2007

On 29 October 1993 the Government finally gave its consent and financial backing to the £1.9 billion extension of the Jubilee Line underground railway in London after a £400 million contribution from the private sector was secured. This extension will be the biggest addition to the underground system in London since the construction of the Victoria Line in the 1960s.

The extension will take the Jubilee Line from Green Park to Stratford in east London via the South Bank, London's Docklands and the North Greenwich peninsula (Fig. 1). Currently the Jubilee Line links Stanmore in northwest London with Charing Cross in central London. The section of the line between Green Park and Charing Cross will be closed to regular services. The line will contribute to the regeneration of the Docklands, relieve congestion on other underground lines, improve links between existing British Rail termini and bring parts of south and east London within reach of the underground network for the first time.

The extension has a total length of 15.8 km, 10.4 km of which is in twin bored 4.35 m internal diameter running tunnel. The remainder, from the portal at Canning Town to Stratford, is at the surface. It involves the construction of eleven additional stations, eight of which are underground, a new depot at Stratford and a control centre at Neasden Depot as well as an upgrade of the existing line. New station sites will be created at Southwark, Bermondsey, Canada Water, Canary Wharf, North Greenwich and Canning Town.
Prediction of borehole yield in the confined Chalk of the London Basin
Authors: Monkhouse R. A.
Published: November 2007

Over the past 150 years, groundwater has been pumped from deep boreholes penetrating the Chalk aquifer underlying the Palaeogene strata of the London Basin. By studying the performance of these boreholes, particularly by the consideration of a standardized specific capacity, it is possible to delineate those areas in which greater or lesser yields may be obtained, and to predict the yields likely to be obtained from a borehole of given dimensions.
Groundwater vulnerability assessment: two case studies using GIS methodology
Authors: Hiscock K. M. , Lovett A. A. , Brainard J. S. , Parfitt J. P.
Published: November 2007

In the first case study presented here, a geographic information system (GIS) is used to create a groundwater vulnerability map of the Midlands and northwest of England by overlaying regional information on the solid geology, Quaternary drift cover and soil cover. The map reveals that areas of extreme and high groundwater vulnerability occur in the vicinities of Birmingham, Liverpool and Manchester.

In the second study, a GIS is used to create a groundwater vulnerability map for southeast England and to combine this information with results from a routing model for the transport of hazardous aqueous waste within the region. The routing mode utilizes an accident-minimizing scenario and expresses the potential pollution threat to groundwater as the number of tanker-kilometers directed over each groundwater vulnerability class.

It is concluded that a GIS methodology is very suitable for groundwater vulnerability mapping, providing an ability to integrate multiple layers of information and to derive additional information, for example on pollution risks. A GIS also allows flexibility in the revision of maps should existing information become obsolete, or revision of the groundwater vulnerability classification scheme be necessary.
Mapping remote areas using SRTM and ASTER digital elevation model data: a solution to orientation problems
Authors: Dowman I. , Balan P.
Published: November 2007

Digital elevation models (DEMs) are used in many applications and some of them, such as geomorphological or geological applications, need DEMs to be generated over a very large area, with high resolution. As high-resolution sensors cover smaller areas, DEMs could be generated only for those areas that could be mosaiced later to cover the total area. If no ground control points are accessible, individual DEM tiles pose orientation problems during mosaicing, as the stereo models are not adjusted to each other. These orientation problems are addressed in this paper. Differences between the adjacent DEM tiles include tilt and vertical offset. A solution is proposed to remove such tilt and vertical offset and/or to register the relative DEMs to a reference DEM, if available. Results are presented of a case study over part of the Zagros Mountains, Iran, covering 72 065 km
2
. The software tool developed in this study was applied to mosaic 14 ASTER DEMs: no ground control points were used for any of those DEM tiles or for the mosaic. An SRTM DEM of 90 m grid spacing was used to register the mosaic to achieve the absolute orientation.
Developments in synthetic aperture radar interferometry for monitoring geohazards
Authors: Riedmann M. , Haynes M.
Published: November 2007

In 1993 synthetic aperture radar (SAR) interferometry (InSAR) was introduced to the wider remote sensing community with the publication of the interferogram depicting the ground deformation caused by the Landers earthquake. Although the power of interferometry was demonstrated, the conventional technique has not always been applicable in all operational scenarios. Over the last few years, however, a number of technical developments have emerged that provide a higher precision of motion rates, the extraction of specific motion histories, and precise targeting. This paper examines uses of differential SAR interferometry (DifSAR) for monitoring geohazards. Limitations of DifSAR will be discussed: lack of coherence, atmospheric refraction and targeting. It will be shown how some of these limitations can be overcome with persistent scatterer interferometry (PSI), which detects slow ground motion with annual rates of as little as a few millimetres, reconstructing a motion history based on the European Space Agency's SAR image archive. The technique permits the estimation and removal of the atmospheric phase, achieving higher accuracies than DifSAR. PSI relies on the availability of pre-existing ground features that strongly and persistently reflect back the signal from the satellite. However, in highly vegetated regions, PSI may not be applicable because of the lack of natural scatterers. To ensure motion measurement of the ground or structures at targeted locations, the NPA Group is developing InSAR using artificial radar reflectors, such as Corner Reflectors (CRs) or Compact Active Transponders (CATs). Both reflector types are still undergoing validation tests, but results show a high phase stability in both cases.
G Protein–Coupled Receptor Sorting to Endosomes and Lysosomes
Authors: Marchese Adriano , Paing May M. , Temple Brenda R.S. , Trejo JoAnn
Published: November 2007

The heptahelical G protein–coupled receptors (GPCRs) belong to the largest family of cell surface signaling receptors encoded in the human genome. GPCRs signal to diverse extracellular stimuli and control a vast number of physiological responses, making this receptor class the target of nearly half the drugs currently in use. In addition to rapid desensitization, receptor trafficking is crucial for the temporal and spatial control of GPCR signaling. Sorting signals present in the intracytosolic domains of GPCRs regulate trafficking through the endosomal-lysosomal system. GPCR internalization is mediated by serine and threonine phosphorylation and arrestin binding. Short, linear peptide sequences including tyrosine- and dileucine-based motifs, and PDZ ligands that are recognized by distinct endocytic adaptor proteins also mediate internalization and endosomal sorting of GPCRs. We present new data from bioinformatic searches that reveal the presence of these types of sorting signals in the cytoplasmic tails of many known GPCRs. Several recent studies also indicate that the covalent modification of GPCRs with ubiquitin serves as a signal for internalization and lysosomal sorting, expanding the diversity of mechanisms that control trafficking of mammalian GPCRs.
Decline in intestinal mucosal IL-10 expression and decreased intestinal barrier function in a mouse model of total parenteral nutrition
Authors: Sun Xiaoyi , Yang Hua , Nose Keisuke , Nose Satoko , Haxhija Emir Q. , Koga Hiroyuki , Feng Yongjia , Teitelbaum Daniel H.
Published: November 2007

Loss of intestinal epithelial barrier function (EBF) is a major problem associated with total parenteral nutrition (TPN) administration. We have previously identified intestinal intraepithelial lymphocyte (IEL)-derived interferon-γ (IFN-γ) as a contributing factor to this barrier loss. The objective was to determine whether other IEL-derived cytokines may also contribute to intestinal epithelial barrier breakdown. C57BL6J male mice received TPN or enteral nutrition (control) for 7 days. IEL-derived interleukin-10 (IL-10) was then measured. A significant decline in IEL-derived IL-10 expression was seen with TPN administration, a cytokine that has been shown in vitro to maintain tight junction integrity. We hypothesized that this change in IEL-derived IL-10 expression could contribute to TPN-associated barrier loss. An additional group of mice was given exogenous recombinant IL-10. Ussing chamber experiments showed that EBF markedly declined in the TPN group. TPN resulted in a significant decrease of IEL-derived IL-10 expression. The expression of several tight junction molecules also decreased with TPN administration. Exogenous IL-10 administration in TPN mice significantly attenuated the TPN-associated decline in zonula occludens (ZO)-1, E-cadherin, and occludin expression, as well as a loss of intestinal barrier function. TPN administration led to a marked decline in IEL-derived IL-10 expression. This decline was coincident with a loss of intestinal EBF. As the decline was partially attenuated with the administration of exogenous IL-10, our findings suggest that loss of IL-10 may be a contributing mechanism to TPN-associated epithelial barrier loss.
Serum Magnesium Level and Clinical Deterioration in Alzheimer’s Disease
Authors: Çilliler Aslı Ece , Öztürk Şerefnur , Özbakır Şenay
Published: November 2007

Background: Recent studies suggest that magnesium, which specially affects the N-methyl-D-aspartate receptor response to excitatory amino acids, may be a supportive therapeutic agent in Alzheimer’s disease. Objective: To investigate the relationship between magnesium levels and the cognitive test results and clinical stages of the patients. Methods: Thirty-seven patients (20 women, 17 men) and 34 controls were included in the study. The patients were staged according to Global Deterioration Scale (GDS) and Clinical Dementia Rating (CDR). Results: There was a significant difference for Mg levels according to GDS (p = 0.030). Similarly, Mg levels were different between patients with low and high CDR stages (p = 0.003). Mg levels were lower in the group whose MMSE scores were <20 than in those whose MMSE scores were ≧20. A negative correlation was found between Mg levels and GDS and CDR (respectively: r = –0.35, p = 0.033; r = –0.360, p = 0.029). Conclusion: Our data suggest that there is a relationship between serum Mg levels and the degree of Alzheimer’s disease and that the determination of the Mg level at various stages may provide valuable information in further understanding the progression and treatment of Alzheimer’s disease.
Effects of Manganese on Streptococcus mutans Planktonic and Biofilm Growth
Authors: Arirachakaran P. , Luengpailin S. , Banas J.A. , Mazurkiewicz J.E. , Benjavongkulchai E.
Published: November 2007

Streptococcus mutans, an agent of dental caries, was tested for growth in the presence or absence of manganese (Mn), since studies have linked Mn levels with cariogenic potential. Seven S. mutans serotype c strains were grown in chemically defined medium under different atmospheric conditions: 5% CO2, O2-enriched 5% CO2 (shaking) and anaerobic. There was significant strain variability with respect to Mn requirements under the various conditions tested. Both sucrose-dependent and sucrose-independent biofilm growth by strain UA159 were affected by the absence of Mn. S. mutans strains show highly variable responses to both high and low Mn concentrations.
Manganese Affects Streptococcus mutans Virulence Gene Expression
Authors: Arirachakaran P. , Benjavongkulchai E. , Luengpailin S. , Ajdić D. , Banas J.A.
Published: November 2007

Background/Aims: Studies of trace metals in drinking water and tooth enamel have suggested a caries-promoting potential for manganese (Mn). Additionally, Mn has been shown to be essential for the expression of mutans streptococci virulence factors such as the glucan-binding lectin (GBL) of Streptococcus sobrinus. The Streptococcus mutans glucan-binding protein (Gbp) GbpC is the functional analogue of the S. sobrinus GBL. S. mutans Gbps have been shown to contribute to biofilm architecture and virulence. This study was undertaken to examine the effects of Mn on the transcription of genes encoding S. mutans Gbps, including gbpC, along with other critical S. mutans virulence genes. Methods: Microarray analyses suggested the potential for an Mn effect on Gbp genes. Further investigation of the Mn effects on selected genes was undertaken by performing Northern blots, Western blots, and RT-PCR under conditions of planktonic and biofilm growth in Mn-depleted media or in media containing 50 µM Mn. Results: Mn resulted in increased expression of gbpC and gtfB, and decreased expression of wapA, in both planktonic and biofilm cultures. The expression levels of gbpA and gbpD were also decreased in the presence of Mn, but only in biofilms. The expression of gtfC was increased in the presence of Mn only in planktonic cultures. The spaP gene was expressed more highly in Mn-supplemented planktonic cultures but less in Mn-supplemented biofilms. Conclusion: Mn availability affects the expression of multiple S. mutans genes involved in adhesion and biofilm formation. Furthermore, these effects depend on the growth state of the organism.
Accumulation of Myeloperoxidase-Positive Neutrophils in Atherosclerotic Lesions in LDLR
−/−
Mice
Authors: van Leeuwen Marcella , Gijbels Marion J.J. , Duijvestijn Adriaan , Smook Marjan , van de Gaar Marie José , Heeringa Peter , de Winther Menno P.J. , Tervaert Jan Willem Cohen
Published: November 2007

Objective—

Atherosclerosis is a chronic inflammatory disease in which the immune system plays an important role. Neutrophils have not been thoroughly studied in the context of atherogenesis. Here, we investigated neutrophils in the development of murine atherosclerotic lesions.

Methods and Results—

LDLR
−/−
mice were given a high-fat diet for different time periods and subsequently atherosclerotic lesions were studied by immunohistochemistry. Staining with anti–Ly-6G monoclonal antibody, a specific marker for neutrophils, revealed a marked accumulation of neutrophils during atherosclerosis development. Neutrophils were observed in the lesion, attached to the cap, and in the arterial adventitia. In addition, at some sites, neutrophil accumulation colocalized with endothelial E-selectin expression. Immunofluorescence double staining with anti-myeloperoxidase and anti–Ly-6G antibodies demonstrated the presence of myeloperoxidase in atherosclerotic lesions and its colocalization with neutrophils. After introducing the high-fat diet, levels of circulating myeloperoxidase in plasma strongly increased, with a peak at 6 weeks and a subsequent decrease to almost normal levels after 16 weeks of diet.

Conclusions—

We here demonstrate for the first time the presence of neutrophils and myeloperoxidase in murine atherosclerotic lesions. As a major cell type in inflammatory responses the neutrophil may also be an important mediator in the development of atherosclerosis.
TF/FVIIa Transactivate PDGFRβ to Regulate PDGF-BB–Induced Chemotaxis in Different Cell Types
Authors: Siegbahn Agneta , Johnell Matilda , Nordin Anna , Åberg Mikael , Velling Teet
Published: November 2007

Background—

We have previously reported the potentiation of PDGF-BB–induced chemotaxis of fibroblasts, vascular smooth muscle cells, and endothelial cells by FVIIa. Here we studied the role of TF/FVIIa and the induced signaling pathways in regulation of chemotaxis of human monocytes, fibroblasts, and porcine aorta endothelial cells.

Methods and Results—

Human monocytes were obtained by using Ficoll-Paque gradient and the MACS system (for highly purified population), fibroblasts and PAE cells have been characterized previously. Inhibitors of selected signaling intermediates were used, and the effect of TF/FVIIa on the migratory response of all cells to chemotactic agents was analyzed. The induced signaling was studied by immunoprecipitation and Western blotting. TF/FVIIa complex selectively enhanced PDGF-BB–induced chemotaxis in a Src-family, PLC, and PAR-2–dependent manner. Using PAE cells we identified c-Src and c-Yes as the Src-family members activated by TF/FVIIa. We report for the first time the PAR-2 and Src family-dependent transactivation of PDGFRβ by TF/FVIIa involving phosphorylation of a subset of PDGFRβ tyrosines.

Conclusions—

The described transactivation is a likely mechanism of TF/FVIIa-mediated regulation of PDGF-BB–induced chemotaxis. Similar behavior of 3 principally different cell types in our experimental setup may reflect a general function of TF in regulation of cell migration.
Protective Role of CXC Receptor 4/CXC Ligand 12 Unveils the Importance of Neutrophils in Atherosclerosis
Authors: Zernecke Alma , Bot Ilze , Djalali-Talab Yassin , Shagdarsuren Erdenechimeg , Bidzhekov Kiril , Meiler Svenja , Krohn Regina , Schober Andreas , Sperandio Markus , Soehnlein Oliver , Bornemann Jörg , Tacke Frank , Biessen Erik A. , Weber Christian
Published: November 2007

The CXC ligand (CXCL)12/CXC receptor (CXCR)4 chemokine–receptor axis controls hematopoiesis, organ development, and angiogenesis, but its role in the inflammatory pathogenesis of atherosclerosis is unknown. Here we show that interference with Cxcl12/Cxcr4 by a small-molecule antagonist, genetic
Cxcr4
deficiency, or lentiviral transduction with Cxcr4 degrakine in bone marrow chimeras aggravated diet-induced atherosclerosis in apolipoprotein E-deficient (
Apoe
−/−
) or LDL receptor–deficient (
Ldlr
−/−
) mice. Chronic blockade of Cxcr4 caused leukocytosis and an expansion of neutrophils and increased neutrophil content in plaques, associated with apoptosis and a proinflammatory phenotype. Whereas circulating neutrophils were recruited to atherosclerotic lesions, depletion of neutrophils reduced plaque formation and prevented its exacerbation after blocking Cxcr4. Disrupting Cxcl12/Cxcr4 thus promotes lesion formation through deranged neutrophil homeostasis, indicating that Cxcl12/Cxcr4 controls the important contribution of neutrophils to atherogenesis in mice
Hyperoxia Increases Phosphodiesterase 5 Expression and Activity in Ovine Fetal Pulmonary Artery Smooth Muscle Cells
Authors: Farrow Kathryn N. , Groh Beezly S. , Schumacker Paul T. , Lakshminrusimha Satyan , Czech Lyubov , Gugino Sylvia F. , Russell James A. , Steinhorn Robin H.
Published: November 2007

In the pulmonary vasculature, cGMP concentrations are regulated in part by a cGMP-dependent phosphodiesterase (PDE), PDE5. Infants with persistent pulmonary hypertension of the newborn (PPHN) are often mechanically ventilated with high oxygen concentrations. The effects of hyperoxia on the developing pulmonary vasculature and PDE5 are largely unknown. Here, we demonstrate that exposure of fetal pulmonary artery smooth muscle cells (FPASMCs) to high levels of oxygen for 24 hours leads to decreased responsiveness to exogenous NO, as determined by a decreased intracellular cGMP response, increased PDE5 mRNA and protein expression, as well as increased PDE5 cGMP hydrolytic activity. We demonstrate that inhibition of PDE5 activity with sildenafil partially rescues cGMP responsiveness to exogenous NO. In FPASMCs, hyperoxia leads to increased oxidative stress without increasing cell death. Treatment of normoxic FPASMCs with H2O2is sufficient to induce PDE5 expression and activity, suggesting that reactive oxygen species mediate the effects of hyperoxia in FPASMCs. In support of this mechanism, a chemical antioxidant,N-acetyl-cysteine, is sufficient to block the hyperoxia-mediated increase in PDE5 expression and activity and rescue cGMP responsiveness to exogenous NO. Finally, ventilation of healthy neonatal sheep with 100% O2for 24 hours leads to increased PDE5 protein expression in the resistance pulmonary arteries and increased PDE5 activity in whole lung extracts. These data suggest that PDE5 expression and activity play a critical role in modulating neonatal pulmonary vascular tone in response to common clinical treatments for PPHN, such as oxygen and inhaled NO.
Astrocyte-Derived CO Is a Diffusible Messenger That Mediates Glutamate-Induced Cerebral Arteriolar Dilation by Activating Smooth Muscle Cell K
Ca
Channels
Authors: Li Anlong , Xi Qi , Umstot Edward S. , Bellner Lars , Schwartzman Michal L. , Jaggar Jonathan H. , Leffler Charles W.
Published: November 2007

Astrocyte signals can modulate arteriolar tone, contributing to regulation of cerebral blood flow, but specific intercellular communication mechanisms are unclear. Here we used isolated cerebral arteriole myocytes, astrocytes, and brain slices to investigate whether carbon monoxide (CO) generated by the enzyme heme oxygenase (HO) acts as an astrocyte-to-myocyte gasotransmitter in the brain. Glutamate stimulated CO production by astrocytes with intact HO-2, but not those genetically deficient in HO-2. Glutamate activated transient K
Ca
currents and single K
Ca
channels in myocytes that were in contact with astrocytes, but did not affect K
Ca
channel activity in myocytes that were alone. Pretreatment of astrocytes with chromium mesoporphyrin (CrMP), a HO inhibitor, or genetic ablation of HO-2 prevented glutamate-induced activation of myocyte transient K
Ca
currents and K
Ca
channels. Glutamate decreased arteriole myocyte intracellular Ca
2+
concentration and dilated brain slice arterioles and this decrease and dilation were blocked by CrMP. Brain slice arteriole dilation to glutamate was also blocked by L-2-alpha aminoadipic acid, a selective astrocyte toxin, and paxilline, a K
Ca
channel blocker. These data indicate that an astrocytic signal, notably HO-2–derived CO, is used by glutamate to stimulate arteriole myocyte K
Ca
channels and dilate cerebral arterioles. Our study explains the astrocyte and HO dependence of glutamatergic functional hyperemia observed in the newborn cerebrovascular circulation in vivo.
Adiponectin Inhibits the Production of CXC Receptor 3 Chemokine Ligands in Macrophages and Reduces T-Lymphocyte Recruitment in Atherogenesis
Authors: Okamoto Yoshihisa , Folco Eduardo J. , Minami Manabu , Wara A.K. , Feinberg Mark W. , Sukhova Galina K. , Colvin Richard A. , Kihara Shinji , Funahashi Tohru , Luster Andrew D. , Libby Peter
Published: November 2007

Obese individuals often have low plasma adiponectin and concomitant chronic inflammation with a predisposition to metabolic and cardiovascular diseases. The present study reports a novel antiinflammatory action of adiponectin in human monocyte-derived macrophages (MΦ) suppressing T-lymphocyte accumulation in atherogenesis. RNA profiling of lipopolysaccharide-stimulated human MΦ identified CXC chemokine ligands (CXCLs), such as IP-10 (interferon [IFN]-inducible protein 10) (CXCL10), I-TAC (IFN-inducible T-cell α chemoattractant) (CXCL11), and Mig (monokine induced by IFN-γ) (CXCL9), T-lymphocyte chemoattractants associated with atherogenesis, among the top 14 transcripts suppressed by adiponectin. Real-time quantitative RT-PCR and ELISA verified that adiponectin inhibited expression of these chemokines at both the mRNA and protein levels in a concentration-dependent manner. Adiponectin reduced the release by lipopolysaccharide-stimulated MΦ of chemoattractant activity for CXC chemokine receptor 3–transfected (receptor for IP-10, Mig, and I-TAC) lymphocytes. Adiponectin decreased lipopolysaccharide-inducible IP-10 promoter activity in promoter-transfected THP-1 MΦ but did not change IP-10 mRNA stability. In lipopolysaccharide-stimulated MΦ, reduction of IFN-β by adiponectin preceded inhibition of IP-10 mRNA expression. Immunoblot and chromatin immunoprecipitation analyses demonstrated that adiponectin attenuated activation of the transcription factor IFN regulatory factor 3, involved in the MyD88-independent pathway of Toll-like receptor 4 signaling, and subsequent IFN regulatory factor 3 binding to IFN-β promoter. In vivo studies further demonstrated that apolipoprotein E/adiponectin double-deficient (apoE
−/−
APN
−/−
) mice had increased plasma IP-10 levels, accelerated T-lymphocyte accumulation in atheromata, and augmented atherogenesis compared with apoE single-deficient (apoE
−/−
APN
+/+
) mice. This study establishes that low levels of adiponectin associated with obesity, the metabolic syndrome, and diabetes favor T-lymphocyte recruitment and contribute to adaptive immune response during atherogenesis.
Abnormal Conduction and Morphology in the Atrioventricular Node of Mice With Atrioventricular Canal–Targeted Deletion of Alk3/Bmpr1a Receptor
Authors: Stroud Dina Myers , Gaussin Vinciane , Burch John B.E. , Yu Cindy , Mishina Yuji , Schneider Michael D. , Fishman Glenn I. , Morley Gregory E.
Published: November 2007

Background—

The atrioventricular (AV) node is essential for the sequential excitation and optimized contraction of the adult multichambered heart; however, relatively little is known about its formation from the embryonic AV canal. A recent study demonstrated that signaling by Alk3, the type 1a receptor for bone morphogenetic proteins, in the myocardium of the AV canal was required for the development of both the AV valves and annulus fibrosus. To test the hypothesis that bone morphogenetic protein signaling also plays a role in AV node formation, we investigated conduction system function and AV node morphology in adult mice with conditional deletion of Alk3 in the AV canal.

Methods and Results—

High-resolution optical mapping with correlative histological analysis of 28 mutant hearts revealed 4 basic phenotypic classes based on electrical activation patterns and volume-conducted ECGs. The frequency of AV node conduction and morphological abnormalities increased from no detectable anomalies (class I) to severe defects (class IV), which included the presence of bypass tracts, abnormal ventricular activation patterns, fibrosis of the AV node, and twin AV nodes.

Conclusion—

The present findings demonstrate that bone morphogenetic protein signaling is required in the myocardium of the AV canal for proper AV junction development, including the AV node.
Relationship Between Retinal Arteriolar Narrowing and Myocardial Perfusion
Authors: Wang Lu , Wong Tien Y. , Sharrett A. Richey , Klein Ronald , Folsom Aaron R. , Jerosch-Herold Michael
Published: November 2007

Retinal arteriolar narrowing is a marker of chronic hypertension. Myocardial perfusion reflects microvascular processes in the heart. The relationship between these 2 measures has not been studied previously and is examined in 212 men and women aged 45 to 84 years and free of cardiovascular disease diagnoses. Retinal caliber was measured through fundus photography and presented as central retinal arteriolar and venular caliber equivalents. Myocardial blood flow was measured using MRI during rest and adenosine-induced hyperemia. Among subjects with no coronary artery calcification (n=98), smaller retinal arteriolar caliber was associated with lower hyperemic myocardial blood flow and perfusion reserve (calculated as the ratio of hyperemic:resting blood flow). Mean hyperemic blood flow (3.43, 3.28, 3.26, and 3.09 mL/min per gram;
P
linear
=0.006) and mean perfusion reserve (3.52, 3.37, 3.19, and 3.10;
P
linear
=0.01) progressively decreased across decreasing quartiles of retinal arteriolar caliber. These associations remained significant after adjusting for age, gender, and race/ethnicity but were no longer significant after additionally adjusting for other cardiovascular risk factors. In contrast, among subjects with coronary calcification (n=114), retinal arteriolar caliber was not associated with hyperemic myocardial blood flow (
P
linear
=0.73) or perfusion reserve (
P
linear
=0.79). There were no associations between retinal venular caliber and perfusion measurements. We conclude that narrower retinal arterioles were associated with lower hyperemic myocardial blood flow and perfusion reserve in asymptomatic adults with no coronary calcification, which is partially mediated by traditional cardiovascular risk factors. This finding suggests that retinal arteriolar narrowing may serve as a marker of coronary microvascular disease.
Goal-Directed Fluid Management by Bedside Transpulmonary Hemodynamic Monitoring After Subarachnoid Hemorrhage
Authors: Mutoh Tatsushi , Kazumata Ken , Ajiki Minoru , Ushikoshi Satoshi , Terasaka Shunsuke
Published: November 2007

Background and Purpose—

Optimal monitoring of cardiac output and intravascular volume is of paramount importance for good fluid management of patients with subarachnoid hemorrhage (SAH). The aim of this study was to demonstrate the feasibility of advanced hemodynamic monitoring with transpulmonary thermodilution and to provide descriptive data early after SAH.

Methods—

Forty-six patients with SAH treated within 24 hours of the ictus were investigated. Specific targets for cardiac index (≥3.0 L · min
−1
· m
−2
), global end-diastolic volume index (700 to 900 mL/m
2
), and extravascular lung water index (≤14 mL/kg) were established by the single-indicator transpulmonary thermodilution technique, and a fluid management protocol emphasizing supplemental colloid administration was used to attain these targets. Plasma hormones related to stress and fluid regulation were also measured.

Results—

A higher cardiac index (mean value of 5.3 L · min
−1
· m
−2
) and a lower global end-diastolic volume index (555 mL/m
2
) were observed on initial measurement, for which elevations of plasma adrenaline, noradrenaline, and cortisol were also detected. Cardiac index was progressively decreased (3.5 L · min
−1
· m
−2
) and global end-diastolic volume index was normalized by fluid administration aimed at normovolemia. The extent of the initial hemodynamic and hormonal profile was greater in patients with a poor clinical status (
P
<0.05). The extravascular lung water index was mildly elevated but within the target range throughout the study period. No patients developed pulmonary edema or congestive heart failure.

Conclusions—

The impact of sympathetic hyperactivity after SAH predisposes patients to a hyperdynamic and hypovolemic state, especially in those whose clinical status is poor. Bedside monitoring with the transpulmonary thermodilution system may be a powerful tool for the systemic management of such patients.
Performing in Ambient Narratives: Supporting Everyday Life Performances with Technology
Authors: van Doorn Mark , van Loenen Evert , de Vries Arjen
Published: November 2007

Consumer electronics, telecommunications, and computing increasingly inhabit the background of everyday life—guiding people's behavior sometimes without their knowledge. What are the possibilities and limitations of ambient intelligence? What will the future bring as the boundaries between the real and the virtual dissolve?
Playback Theatre: Inciting Dialogue and Building Community through Personal Story
Authors: Fox Hannah
Published: November 2007

The Playback Theatre method is humble: trained performers act out life stories volunteered by audience members. Playback Theatre's goal is to illuminate social problems and resolve them. Like Boal's Theatre of the Oppressed, Playback Theatre strives to give voice and visibility to those overlooked and ignored.
On Sudbury-Area Wind Speeds—A Tale of Forest Regeneration
Authors: Tanentzap Andrew J. , Taylor Peter A. , Yan Norman D. , Salmon James R.
Published: November 2007

A 34% reduction in 10-m wind speeds at Sudbury Airport in Ontario, Canada, over the period 1975–95 appears to be a result of significant changes in the surface roughness of the surrounding area that are due to land restoration and reforestation following historical environmental damage caused by high sulfur dioxide and other industrial emissions. Neither 850-hPa winds extracted from the NCEP–NCAR reanalysis database nor wind measurements at meteorological stations 200 km to the north and 120 km to the east of Sudbury show the same decrease. To assess these changes in observed wind speed quantitatively, geostrophic drag laws were employed to illustrate potential changes in near-surface wind speeds in areas surrounding the airport. A model of the internal boundary layer flow adjustment associated with changes in the surface roughness length between the surroundings and the grass or snow surface of the airport was then applied to compute expected annual average wind speeds at the airport site itself. The estimates obtained with this relatively simple procedure match the observations and confirm that reforestation is likely the major cause of the reduced wind speeds. This finding bears economic, social, and ecological importance, because it will influence wind energy potential, wind loads on structures, wind chill, and home heating costs through to the biology of small- to medium-sized lakes.
Identifying Weather Regimes in the Wintertime 500-hPa Geopotential Height Field for the Pacific–North American Sector Using a Limited-Contour Clustering Technique
Authors: Casola Joseph H. , Wallace John M.
Published: November 2007

A hierarchical clustering algorithm using Ward’s method has been applied to the 500-hPa geopotential height field in the Pacific–North American sector. In contrast to previous clustering studies that measure distance between records by using all the grid points within the domain (full-field method), the procedure outlined here, referred to as the limited-contour method, focuses on the coordinates of the 540-dam contour as the distance measure. Comparison between the regimes emerging from the two methods shows that the limited-contour method is more efficient than the full-field method with respect to grouping maps with ridges located at similar longitudes. The four regimes emerging from the limited-contour clustering analysis have been named as follows: Off-Shore Trough, Alaskan Ridge, Coastal Ridge, and Rockies Ridge. The frequencies of occurrence of the regimes have a significant relationship with the phase of the El Niño–Southern Oscillation. El Niño winters exhibit a strong preference for the Rockies Ridge pattern; La Niña winters exhibit a greater diversity of regimes. The frequencies of occurrence of extreme cold outbreaks and episodes of heavy precipitation in the Pacific Northwest show a relatively strong connection to the regime type. For other regions in the western portion of the United States, only the frequency of occurrence of cold outbreaks exhibits a significant relationship to regime type.
Changes in the Practice of Eating
Authors: Warde Alan , Cheng Shu-Li , Olsen Wendy , Southerton Dale
Published: November 2007

This article examines changes in aspects of the eating habits of the populations of five countries between the early 1970s and the end of the 1990s. Time-use diary data provide the main evidence, which is subjected to techniques of statistical description and regression analysis. The study of France, UK, USA, Norway and the Netherlands shows considerable national variation in patterns of food preparation, eating at home and eating out. Each of these components of the practice of eating is examined for indications of whether there are any tendencies towards dedifferentiation within countries or convergence across countries. There are some common patterns across countries, notably a decline in the amount of time devoted to food preparation. Time spent on eating at home reduces in all countries except France. In the USA, time devoted to domestic food preparation and consumption is minimal. Internal differentiation shows continuities — of gender divisions and age-related behaviour — but also new emergent tendencies — with the presence of children and levels of cultural capital becoming significant predictors of behaviour. It is maintained that the analysis of time-use provides a useful framework for comparing practices in different countries and that the variation revealed might best be understood in terms of different modes of institutionalization of consumption.
Breaking Up the Different Constituting Parts of Ethnicity
Authors: Fangen Katrine
Published: November 2007

How do young Somalis in Norway conceptualize their sense of position and belonging? How do they relate to different entities such as Norway, Somalia, the Somali community in Norway and friends from different ethnic groups? I discuss young Somalis' narratives of location in light of debates in contemporary identity theory. The article is a case study of five young Somalis who were part of a sample of 40 Somalis interviewed during the period 2003—2007.
Towards reality and away from blind acceptance: Changes in the attitude of public house bar staff to their exposure to second hand tobacco smoke in the work-place since the announcement of legislative measures
Authors: Adams Jones Marc , Adams Jones David , Powell Colin
Published: November 2007

Attitudes of bar staff to second hand tobacco smoke in the workplace were investigated in 2001 by means of a questionnaire. At that time, government policy favoured voluntary agreements with the hospitality industry. In 2006, when policy had changed and legislation was imminent, the same questionnaire was used to measure the change in attitude over the five-year period. The main findings were:

• bar staff had become significantly less tolerant of second hand smoke between 2001 and 2006.

• bar staff who smoked had become significantly more supportive of the introduction of a smoking policy by 2006

• the significant majority considering a smoking policy to be impractical in 2001 had disappeared by 2006.

• in 2006 it was still the majority view that smoking was an integral part of pub life and that smoking policies would interfere with customers' enjoyment.

The message is therefore that there has been significant movement towards acceptance of a ban on smoking in the workplace. Enforcement of this ban, however, could be difficult in view of the still widespread view that smoking and public houses have some sort of special relationship.
An American perspective on the implications for business and health care of the Nordic welfare model
Authors: Odom Sue E. , Deis Michael H.
Published: November 2007

With the emergence of a global economy, it is imperative that faculty have an increased understanding of variables or factors affecting the welfare and health care systems of different countries. In addition, they must become knowledgeable about how the European Union plays a part in the evolution of these systems and be aware of the business implications of them. This paper discusses and highlights how two countries, Sweden and Denmark, are dealing with these challenges. Based on two professors' travel experiences, personal reflections are shared and contrasted with similar issues in the United States. The paper should be applicable for both business and health care professionals in academia.
Co-workers who telework and the impact on those in the office: Understanding the implications of virtual work for co-worker satisfaction and turnover intentions
Authors: Golden Timothy
Published: November 2007

Telework and other forms of virtual work have experienced dramatic growth over the last decade. While research is beginning to understand its impacts on teleworkers themselves, studies to date have not looked at its effect on those who remain in the office. This study therefore shifts the focus to non-teleworkers in offices where telework is present, to investigate if the prevalence of teleworkers in an office impacts the work outcomes of non-teleworkers. Using a sample of 240 professional employees, results suggest teleworker prevalence is negatively associated with co-worker satisfaction, and that this relationship is influenced by the amount of time co-workers telework, the extent of face-to-face interactions, and job autonomy. Moreover, a non-teleworker's satisfaction with co-workers was also found to be negatively associated with turnover intentions. Together, results suggest the need to consider the full range of telework's impacts including the potential adverse consequences for non-teleworkers.
China's Labour Law, Compliance and Flaws in Implementing Institutions
Authors: Cooney Sean
Published: November 2007

This article examines some of the factors contributing to the widespread compliance failures experienced by Chinese labour law. It focuses on the nature of the legal rules and the structure of state and quasi-state institutions charged with implementing the law. While the basic legal framework regulating labour in China appears designed to prevent many abuses, the lack of settled detail inhibits effective enforcement. The labour inspectorate, formal dispute resolution processes and the official trade union organization each suffer from weaknesses reducing their capacity to elicit compliance with the law. Some improvements to the law and the institutions are already being implemented. The article suggests further areas of reform that may increase compliance, within the constraints of China's current political realities.
Ethical Purchasing and Workers' Rights in China: The Case of the Brotherhood of St Laurence
Authors: Lillywhite Serena
Published: November 2007

As China continues its economic development and integration with the global economy, pressure is building to ensure international enterprises embrace responsible supply chain management and contribute to improved labour and environmental conditions. Despite China's reputation for having a poor regulatory framework, China's labour law is more comprehensive than that of many Organisation for Economic Co-operation and Development (OECD) countries. What is lacking is an adequate system of enforcement. This article draws on the experiences of an Australian non-governmental organization (NGO) in dealing with the Chinese optical industry to consider the important question of corporate social responsibility in China.1 It begins with an overview of the Brotherhood of St Laurence experience and observations in China, examines the challenges and opportunities of responsible supply chain management and ethical purchasing and the impact on workers' rights, and finally looks at implications for an Australia—China Free Trade Agreement (ACFTA).
Parallel Performance Modeling using a Genetic Programming-based Error Correction Procedure
Authors: Raghavachar Kavitha , Mahinthakumar G. , Worley Patrick , Zechman Emily , Ranjithan Ranji
Published: November 2007

Performance models of high performance computing (HPC) applications are important for several reasons. First, they provide insight to designers of HPC systems on the role of subsystems such as the processor or the network in determining application performance. Second, they allow HPC centers more accurately to target procurements to resource requirements. Third, they can be used to identify application performance bottlenecks and to provide insights about scalability issues. The suitability of a performance model, however, for a particular performance investigation is a function of both the accuracy and the cost of the model.

A semi-empirical model previously published by the authors for an astrophysics application was shown to be inaccurate when predicting communication cost for large numbers of processors. It is hypothesized that this deficiency is due to the inability of the model adequately to capture communication contention (threshold effects) as well as other unmodeled components such as noise and I/O contention. In this paper we present a new approach to capture these unknown features to improve the predictive capabilities of the model. This approach uses a systematic model error-correction procedure that uses evolutionary algorithms to find an error correction term to augment the eXisting model. Four variations of this procedure were investigated and all were shown to produce better results than the original model. Successful cross-platform application of this approach showed that it adequately captures machine dependent characteristics. This approach was then successfully demonstrated for a second application, further showing its versatility.
Using Permuted States and Validated Simulation to Analyze Conflict Rates in Optimistic Replication
Authors: Wang An-I Andy , Kuenning Geoff , Reiher Peter
Published: November 2007

Optimistic replication provides high data availability in the presence of network outages. Although widely deployed, this relaXed consistency model introduces concurrent updates, whose behavior is poorly understood due to the vast state space.

This paper introduces the notion of permuted states to eliminate system states that are redundant and unreachable, which can constitute the majority of states (4069 out of 4096 for four replicas). With the aid of permuted states, we are for the first time able to construct analytical models beyond the two-replica case. By eXamining the analysis for 2 to 4 replicas, we can demystify the process of forming identical conflicts—the most common conflict type at high replication factors. Additionally, we have automated and optimized the generation of permuted states, which allows us to eXplore higher replication factors (up to 10 replicas) using hybrid techniques. It also allows us to validate our results with eXisting simulations based on actual replication mechanisms, which previously were analytically validated with only one pair of replicas.

Finally, we have discovered that update locality and bimodal access patterns are the primary factors contributing to the formation of identical conflicts.