bluuebunny/crossref_metadata_2025 huggingface dataset:
Pressure dependence of thermal transport properties
Authors: Hofmeister Anne M.
Published: February 2007

Pressure (
P
) derivatives of thermal conductivity (
k
) and thermal diffusivity (
D
) are important to geophysics but are difficult to measure accurately because minerals, being hard and partially transparent, likely incur systematic errors through thermal losses at interfaces and spurious radiative transfer. To evaluate accuracy, repeat experiments for olivine [(Mg
0.9
Fe
0.1
)
2
SiO
4
], quartz (SiO
2
), and NaCl are examined in detail: these and other data on electrical insulators are compared with theory. At ambient conditions,
D
is underestimated in proportion to the number of contacts. As temperature (
T
) increases, spurious radiative transfer more than offsets contact loss. Compression of pore space and contact losses affect pressure derivatives, but these seem independent of
T
. Accurate (±2%) values of
D
(
T
) at 1 atm are obtained with the contact-free, laser-flash method. Other optical techniques do not pinpoint
D
but provide useful pressure derivatives. Published data on ∂(ln
k
)/∂
P
at ambient conditions agree roughly with all available models, the simplest of which predicts ∂(ln
k
)/∂
P
∼ ∂(ln
K
T
)/∂
P
, where
K
T
is the bulk modulus. However, derivatives verified by multiple measurements are reproduced accurately only by the damped harmonic oscillator model. An improved database is needed to refine this model and to confidently extrapolate these difficult measurements to geophysically relevant conditions.
Dido
disruption leads to centrosome amplification and mitotic checkpoint defects compromising chromosome stability
Authors: Trachana Varvara , van Wely Karel H. M. , Guerrero Astrid Alonso , Fütterer Agnes , Martínez-A Carlos
Published: February 2007

Numerical and/or structural centrosome abnormalities have been correlated with most solid tumors and hematological malignancies. Tumorigenesis also is linked to defects in the mitotic or spindle assembly checkpoint, a key control mechanism that ensures accurate segregation of chromosomes during mitosis. We have reported that targeted disruption of the
Dido
gene causes a transplantable myelodysplastic/myeloproliferative disease in mice. Here, we report that Dido3, the largest splice variant of the
Dido
gene, is a centrosome-associated protein whose disruption leads to supernumerary centrosomes, failure to maintain cellular mitotic arrest, and early degradation of the mitotic checkpoint protein BubR1. These aberrations result in enhanced aneuploidy in the
Dido
mutant cells.
Dido
gene malfunction thus is reported to be part of an impaired signaling cascade that results in a defective mitotic checkpoint, leading to chromosome instability.
Receptors of the protein C activation and activated protein C signaling pathways are colocalized in lipid rafts of endothelial cells
Authors: Bae Jong-Sup , Yang Likui , Rezaie Alireza R.
Published: February 2007

Ever-increasing evidence in the literature suggests that the antiinflammatory and cytoprotective properties of activated protein C (APC) are mediated through its endothelial protein C receptor (EPCR)-dependent cleavage of protease-activated receptor 1 (PAR-1) on endothelial cells. However, recent results monitoring the cleavage rate of PAR-1 on human umbilical vein endothelial cells, transfected with an alkaline phosphatase–PAR-1 fusion reporter construct, have indicated that the catalytic activity of thrombin toward PAR-1 is several orders of magnitude higher than that of APC. Because thrombin is required for generation of APC, and because it also functions in the proinflammatory pathways through the activation of PAR-1, it has been difficult to understand how APC can elicit protective cellular responses through the activation of PAR-1 when thrombin is present. In this study we provide a plausible answer to this question by demonstrating that the critical receptors required for both protein C activation (thrombomodulin and EPCR) and APC cellular signaling (EPCR and PAR-1) pathways are colocalized in the membrane lipid rafts in endothelial cells. We further show that the APC cleavage of PAR-1 on cells transfected with a PAR-1 cleavage reporter construct is not sensitive to the cofactor function of EPCR. Thus, the colocalization of EPCR and PAR-1 in lipid rafts is a key requirement for the cellular signaling activity of APC. Thrombomodulin colocalization with these receptors on the same membrane microdomain can also recruit thrombin to activate the EPCR-bound protein C, thereby eliciting PAR-1 signaling events that are involved in the APC protective pathways.
Comparison of genetic diversity at microsatellite loci in near‐extinct and non‐endangered species of Mexican goodeine fishes and prediction of cross‐amplification within the family
Authors: Hamill R. M. , Webb S. A. , Macías Garcia C. , Graves J. A. , Magurran A. E. , Ritchie M. G.
Published: February 2007

The cross‐utility of 12 microsatellite loci (including nine newly developed loci) amongst the viviparous subfamily, the Mexican Goodeinae, was assessed, examining both the probability of amplification and the potential incidence of null alleles from tests of FIS. Genetic diversity was relatively high in comparison to other freshwater species. Amplification success was not correlated with genetic distance between microsatellite source and target species, but taxa that were more distantly related were less likely to be cross‐polymorphic for microsatellite loci. On average, species that were cross‐polymorphic were separated by a genetic distance of 15% at the cytochrome oxidase I locus, while those that were monomorphic were separated by 19%. There was no evidence that null alleles become more frequent at greater source‐target genetic distance.
Status of non‐cultivated food plants in Bulamogi County, Uganda
Authors: Tabuti J. R. S.
Published: February 2007

This study was carried out to document the non‐cultivated food plants (NCFPs) of Bulamogi County, Uganda. It formed part of a wider study meant to document all edible plant species in the county with the general aim of strengthening food security. The study was conducted using semi‐structured interviews. Fifty‐nine NCFPs were recorded in the county. These grow as weeds, wild plants and semi‐cultivated crops. They are equally distributed between herbaceous (54%) and woody (46%) growth habits. They yield fruits (31, n = 59), leaves (11, n = 59) or leaves and stems (10, n = 59) for consumption. A short list of 27 NCFPs with potential for domestication is suggested here for further study.
Takotsubo cardiomyopathy: an uncommon cause of ST segment elevation in Intensive Care*
Authors: Bennett J. R. , McCarty D. , Wilson C. M. , O'Neill F.
Published: February 2007

A 63‐year‐old female developed respiratory failure and was admitted to the Intensive Care Unit for non‐invasive ventilation, inotropic support and antibiotic therapy. The patient was initially stable but then suddenly deteriorated with acute pulmonary oedema requiring mechanical ventilation. An electrocardiogram showed an acute ST elevation myocardial infarction and the patient subsequently had an urgent coronary angiogram which revealed normal coronary arteries but apical ballooning characteristic of Takotsubo cardiomyopathy. A short review is provided of this relatively newly described heart syndrome which has the potential to present in numbers of intensive care patients. This case emphasises the importance of being aware of uncommon causes of acute ECG changes in the critically ill.
Effect of light and predator abundance on the habitat choice of plant‐attached zooplankton
Authors: NURMINEN LEENA , HORPPILA JUKKA , PEKCAN‐HEKIM ZEYNEP
Published: February 2007

1. The diurnal variations in the habitat choice of the periodically plant‐attached cladoceran Sida crystallina together with light environment and predator abundance were studied.

2. The density of S. crystallina attached to floating leaves of Nuphar lutea increased between 18:00 and 20:00 hours, when light intensity underneath the leaves was temporarily increased, and decreased again when light intensity declined. A proportion of S. crystallina remained in the swimming mode underneath the leaves even during daylight, indicating that the water column sheltered by the leaves is safer than the open water.

3. In the water adjacent to the leaves, the density of S. crystallina increased steeply in the dark. The increase was not accompanied by a decrease in S. crystallina attached to plant leaves, indicating that the nocturnal increment in the open water density of S. crystallina was due to migration from daytime refuges other than floating leaves.

4. Sida crystallina was most intensively consumed by perch (Perca fluviatilis). Predation threat by fish had weaker effects on the density of S. crystallina attached to plant leaves than on cladocerans in the adjacent water. Cladocerans underneath floating plant leaves, whether attached or not, are probably less vulnerable to fish predation than those outside the leaf cover.

5. The results suggested that light intensity is the proximate factor regulating the attachment of zooplankton to the lower surfaces of floating macrophyte leaves. Light intensity has a positive effect on the density of S. crystallina attached to the floating leaves and a negative effect on density in the water. Predation threat by fish has a strong effect on the migration of zooplankters into the open water habitat.
A derivative‐based interpretation approach to estimating source parameters of simple 2D magnetic sources from Euler deconvolution, the analytic‐signal method and analytical expressions of the anomalies
Authors: Doo Wen‐Bin , Hsu Shu‐Kun , Yeh Yi‐Ching
Published: February 2007

The major advantage of using either the analytic‐signal or the Euler‐deconvolution technique is that we can determine magnetic‐source locations and depths independently of the ambient earth magnetic parameters. In this study, we propose adopting a joint analysis of the analytic signal and Euler deconvolution to estimate the parameters of 2D magnetic sources. The results can avoid solution bias from an inappropriate magnetic datum level and can determine the horizontal locations, depths, structural types (indices), magnetization contrasts and/or structural dips. We have demonstrated the feasibility of the proposed method on 2D synthetic models, such as magnetic contacts (faults), thin dikes and cylinders. However, the method fails to solve the parameters of magnetic sources if there is severe interference between the anomalies of two adjacent magnetic sources.
Constraints on velocity‐depth trends from rock physics models
Authors: Japsen Peter , Mukerji Tapan , Mavko Gary
Published: February 2007

Estimates of depth, overpressure and amount of exhumation based on sonic data for a sedimentary formation rely on identification of a normal velocity–depth trend for the formation. Such trends describe how sonic velocity increases with depth in relatively homogeneous, brine‐saturated sedimentary formations as porosity is reduced during normal compaction (mechanical and chemical). Compaction is ‘normal’ when the fluid pressure is hydrostatic and the thickness of the overburden has not been reduced by exhumation. We suggest that normal porosity at the surface for a given lithology should be constrained by its critical porosity, i.e. the porosity limit above which a particular sediment exists only as a suspension. Consequently, normal velocity at the surface of unconsolidated sediments saturated with brine approaches the velocity of the sediment in suspension. Furthermore, porosity must approach zero at infinite depth, so the velocity approaches the matrix velocity of the rock and the velocity–depth gradient approaches zero. For sediments with initially good grain contact (when porosity is just below the critical porosity), the velocity gradient decreases with depth. By contrast, initially compliant sediments may have a maximum velocity gradient at some depth if we assume that porosity decreases exponentially with depth. We have used published velocity–porosity–depth relationships to formulate normal velocity–depth trends for consolidated sandstone with varying clay content and for marine shale dominated by smectite/illite. The first relationship is based on a modified Voigt trend (porosity scaled by critical porosity) and the second is based on a modified time‐average equation. Baselines for sandstone and shale in the North Sea agree with the established constraints and the shale trend can be applied to predict overpressure. A normal velocity–depth trend for a formation cannot be expressed from an arbitrary choice of mathematical functions and regression parameters, but should be considered as a physical model linked to the velocity–porosity transforms developed in rock physics.
Vegetation loss alters soil nitrogen dynamics in an Arctic salt marsh
Authors: BUCKERIDGE KATE M. , JEFFERIES ROBERT L.
Published: February 2007

Plant and microbial nitrogen (N) dynamics were examined in soils of an Arctic salt marsh beneath goose‐grazed swards and in degraded soils. The degraded soils are the outcome of intensive destructive foraging by geese, which results in vegetation loss and near‐irreversible changes in soil properties. The objective of the study was to determine whether vegetation loss led to a decline in microbial activity and a redistribution of N amongst the different soil N pools that potentially could adversely affect plant regrowth.

In situ N allocation between plants, microbes and soil was determined based on injection of 15NH4Cl into soil cores; changes in isotopic ratios and N concentrations in the different pools were measured after 24 h. Degraded soils, in contrast to vegetated soils, were characterized by a decline in microbial biomass, reduced microbial 15N excess, reduced rates of gross N immobilization and an increased microbial residency time of 15N. In vegetated soils, both microbes and the forage grass, Puccinellia phryganodes, accumulated 15N such that little remained in the soil abiotic phase after 24 h, unlike in degraded soils.

The decline in microbial activity in degraded soils may be linked to a low availability of soil carbon in the absence of plants and to deteriorating abiotic conditions, including the occurrence of hypersalinity in summer.

Not all biotic processes respond similarly to the change in ecosystem state. Unlike vascular plant productivity and goose foraging which are absent in degraded soils, soil microbial activity is maintained, albeit at a lower level. In spite of this activity, the greater proportion of 15N in degraded soils is in the abiotic pool rather than in microbial biomass with an increased potential for soil N loss from leaching and soil erosion.

Disturbance linked to herbivory often triggers catastrophic shifts in ecosystem properties resulting in vegetation loss and changes in soil biogeochemical cycling that are irreversible, at least on a decadal time scale, and lead to the loss of N and other nutrients required for plant growth. These results clearly illustrate that microbial activity does not compensate for the effects of plant removal on soil N retention.
Above‐ and below‐ground competition cues elicit independent responses
Authors: MURPHY GUILLERMO P. , DUDLEY SUSAN A.
Published: February 2007

Plants sharing pots have been observed to show more allocation to roots than do solitary plants, even when resources per plant are constant, indicating plasticity to root neighbours. Lowered red to far‐red ratio (R : FR), a cue of above‐ground competition, is known to cause increased stem elongation and decreased allocation to roots. In nature, however, cues for above‐ and below‐ground competition are likely to be experienced simultaneously, and may elicit contradictory responses.

We investigated whether the presence of the above‐ground competition cue (low R : FR) affected the responses to the below‐ground competition cue (presence of neighbouring roots) in soybean and whether these responses depended on the presence or absence of symbiotic bacteria or on the availability of nutrients.

In a fully factorial study in a growth room, light quality, root neighbours, nutrient availability and Bradyrhizobium inoculation were manipulated. Stem elongation and biomass allocation were measured.

As predicted, plants allocated more to roots in the presence of root neighbours, regardless of R : FR, Bradyrhizobium and nutrient treatment. Plants elongated under low R : FR, although the degree of elongation was affected by Bradyrhizobium and nutrients. R : FR did not affect allocation to roots. Surprisingly, we found no reduction in reproductive allocation and therefore no ‘tragedy of the commons’ cost; instead, growth was increased in the presence of root neighbours.

We conclude that soybean responds to both competition cues independently, but that below‐ground resources such as Bradyrhizobium and nutrient availability moderate the morphological responses to above‐ and below‐ground competition.

To our knowledge, this is the first study that tests responses to above‐ and below‐ground competition cues simultaneously and that shows the independence of these responses. This study provides supporting evidence that plants can sense neighbouring roots as a cue of impending competition and demonstrates clearly that the root allocation response is not dependent on the presence of Bradyrhizobium or an artefact of inadvertent R : FR manipulation.
Frankia alni proteome under nitrogen‐fixing and nitrogen‐replete conditions
Authors: Alloisio Nicole , Félix Servane , Maréchal Joëlle , Pujic Petar , Rouy Zoé , Vallenet David , Medigue Claudine , Normand Philippe
Published: February 2007

Frankia alni induces root nodules on Alnus, in which the bacterium differentiates into nitrogen (N)‐fixing cells called vesicles. In culture, F. alni also undergoes major morphological changes as it alternates between N‐replete and N‐fixing conditions. Lack of biologically available N induces the synthesis of vesicles in which nitrogenase is protected from molecular oxygen by a thick lipid hopanoid envelope. Very little is known about the molecular basis of Frankia–host interaction as well as Frankia cell differentiation. The recent determination of the complete genome sequence of F. alni strain ACN14a has permitted us to characterize its proteome, particularly in the extracellular compartment, which could be involved in Frankia–host interaction, and in the switch from N‐replete to N‐fixing conditions. To that end, 126 bacterial proteins were analyzed by two‐dimensional protein gel electrophoresis and identified by matrix‐assisted laser desorption/ionization time of flight fingerprinting using a F. alni proteome database. Interestingly, the extracellular fraction contains some glycolytic enzymes lacking secretion signals, already reported to be extracellularly localized in some streptococci, as well as some abundant stress‐resistance proteins. As expected, several proteins involved in N assimilation and oxidative defense system were upregulated in F. alni grown under N‐fixing vs N‐replete conditions. Furthermore, two Raf kinase inhibitor protein homologs that could play a role in cellular signaling, and a hemoglobin‐like protein HbN that could be involved in detoxification of nitric oxide were also upregulated. More surprising, a succinate dehydrogenase was strongly downregulated, which could be linked to the need of pyruvate for the biosynthesis of hopanoids or to reduced oxygen diffusion in vesicles.
Functional impairment in patients with mania: baseline results of the EMBLEM study
Authors: Goetz I , Tohen M , Reed C , Lorenzo M , Vieta E ,   the EMBLEM Advisory Board
Published: February 2007

Objectives:  The European Mania in Bipolar Longitudinal Evaluation of Medication (EMBLEM) is a large‐scale prospective observational multicentre study to evaluate the longitudinal course of bipolar disorder and its associations with pharmacological treatment following an acute manic or mixed episode. We present an overview of the study design and patient characteristics at baseline while focusing on factors influencing work performance in the year prior to enrolment.

Methods:  A total of 530 investigators across 14 European countries enrolled 3,681 patients with acute mania between December 2002 and June 2004. Longitudinal observations are ongoing until July 2006. Socio‐demographic variables, psychiatric history, clinical status and information on pharmacological treatment for bipolar disorder were recorded. Items from the SLICE of LIFE were applied, including a measure of work impairment during the previous year. The distribution of the baseline characteristics was analysed with descriptive statistics. Eighteen variables were investigated as hypothesized risk factors for work impairment applying logistic regression models.

Results:  In the previous year, 28 and 68% of patients were classified as having ‘low’ and ‘high’ work impairment, respectively. Clinical Global Impression – Bipolar Disorder (CGI‐BP) overall, CGI‐BP depression at baseline, rapid cycling during the previous 12 months, age between 35 and 64 years, substance abuse other than alcohol and cannabis and living without a partner or as dependent household member were significantly associated with work impairment during the previous year.

Conclusions:  EMBLEM is to our knowledge the largest prospective observational study assessing patients during and after an acute episode of mania. Work impairment is significant in the year prior to an acute episode of mania.
Long‐term social functioning after depression treated by psychiatrists: a review
Authors: Kennedy Noel , Foy Kevin , Sherazi Rafay , McDonough Michael , McKeon Patrick
Published: February 2007

Objectives: Numerous long‐term studies of depression in psychiatric settings have shown a poor clinical outcome but little emphasis has been placed on psychosocial or functional outcome in studies to date. This article reviews published data on long‐term social functioning after depression and considers why psychosocial recovery appears delayed compared with clinical recovery.

Methods: Searches were carried out of the databases MEDLINE, PSYCHLIT and EMBASE for articles published from 1980 using keywords relating to social and functional outcomes of unipolar and bipolar depression. Review articles and relevant textbooks were also searched.

Results: The few outcome studies published have described long‐term functional impairment in the majority of patients but have been limited by methodological shortcomings. Psychosocial impairment tends to persist even after clinical remission from depression. Residual symptomatology after remission from depression may lead to enduring psychosocial impairment, as may subtle neurocognitive deficits. Axis I and II comorbidities predict a poor psychosocial outcome, but episodes of depression do not appear to lead to personality ‘scarring’.

Conclusions: Future outcome studies need to focus on longitudinal social functioning. Full functional recovery after an episode of depression should be the goal of treatment as enduring residual symptoms lead to long‐term psychosocial impairment.
Functional outcome in bipolar disorder: the role of clinical and cognitive factors
Authors: Martinez‐Aran A , Vieta E , Torrent C , Sanchez‐Moreno J , Goikolea JM , Salamero M , Malhi GS , Gonzalez‐Pinto A , Daban C , Alvarez‐Grandi S , Fountoulakis K , Kaprinis G , Tabares‐Seisdedos R , Ayuso‐Mateos JL
Published: February 2007

Introduction: Few studies have examined the clinical, neuropsychological and pharmacological factors involved in the functional outcome of bipolar disorder despite the gap between clinical and functional recovery.

Methods: A sample of 77 euthymic bipolar patients were included in the study. Using ana prioridefinition of low versus good functional outcome, based on the psychosocial items of the Global Assessment of Functioning (GAF, DSM‐IV), and taking also into account their occupational adaptation, the patients were divided into two groups: good or low occupational functioning. Patients with high (n = 46) and low (n = 31) functioning were compared on several clinical, neuropsychological and pharmacological variables and the two patient groups were contrasted with healthy controls (n = 35) on cognitive performance.

Results: High‐ and low‐functioning groups did not differ with respect to clinical variables. However, bipolar patients in general showed poorer cognitive performance than healthy controls. This was most evident in low‐functioning patients and in particular on verbal memory and executive function measures.

Conclusions: Low‐functioning patients were cognitively more impaired than highly functioning patients on verbal recall and executive functions. The variable that best predicted psychosocial functioning in bipolar patients was verbal memory.
Acanthamoeba polyphaga resuscitates viable non‐culturable Legionella pneumophila after disinfection
Authors: García María Teresa , Jones Snake , Pelaz Carmen , Millar Richard D. , Abu Kwaik Yousef
Published: February 2007

Amoebae are the natural hosts for Legionella pneumophila and play essential roles in bacterial ecology and infectivity to humans. When L. pneumophila colonizes an aquatic installation, it can persist for years despite repeated treatments with disinfectants. We hypothesized that freshwater amoebae play an important role in bacterial resistance to disinfectants, and in subsequent resuscitation of viable non‐culturable (VNC) L. pneumophila that results in re‐emergence of the disease‐causing strain in the disinfected water source. Our work showed that in the absence of Acanthamoeba polyphaga, seven L. pneumophila strains became non‐culturable after treatment by 256 p.p.m. of sodium hypochlorite (NaOCl). In contrast, intracellular L. pneumophila within A. polyphaga was resistant to 1024 p.p.m. of NaOCl. In addition, L. pneumophila‐infected A. polyphaga exhibited increased resistance to NaOCl. When chlorine‐sterilized water samples were co‐cultured with A. polyphaga, the non‐culturable L. pneumophila were resuscitated and proliferated robustly within A. polyphaga. Upon treatment by NaOCl, uninfected amoebae differentiated into cysts within 48 h. In contrast, L. pneumophila‐infected A. polyphaga failed to differentiate into cysts, and L. pneumophila was never detected in cysts of A. polyphaga. We conclude that amoebic trophozoites protect intracellular L. pneumophila from eradication by NaOCl, and play an essential role in resuscitation of VNC L. pneumophila in NaOCl‐disinfected water sources. Intracellular L. pneumophila within trophozoites of A. polyphaga block encystation of the amoebae, and the resistance of both organisms to NaOCl is enhanced. To ensure long‐term eradication and complete loss of the VNC state of L. pneumophila, we recommend that Legionella‐protozoa co‐culture should be an important tool to ensure complete loss of the VNC state of L. pneumophila.
INTEL ECONOMICS*
Authors: Segerstrom Paul S.
Published: February 2007

This article presents an endogenous growth model that is designed to be roughly consistent with the experience of high‐tech firms like Intel. In the model, industry leaders invest in R&D to improve their products, small firms invest in R&D to become industry leaders, and innovating becomes progressively more difficult over time. Consistent with the empirical evidence, the model implies that economic growth is independent of economy size and R&D intensity is independent of firm size. For plausible parameter values, it is optimal to heavily subsidize R&D activities.
STATE DEPENDENT PRICING AND BUSINESS CYCLE ASYMMETRIES*
Authors: Devereux Michael B. , Siu Henry E.
Published: February 2007

We present a tractable, dynamic general equilibrium model of state‐dependent pricing and study the response of output and prices to monetary policy shocks. We find important nonlinearities in these responses. For empirically relevant shocks, this generates substantially different predictions from time‐dependent pricing. We also find a distinct asymmetry with state‐dependent pricing: Prices respond more to positive shocks than they do to negative shocks. This is due to a strategic linkage between firms in the incentive for price adjustment. Our state‐dependent model can account for business cycle asymmetries in output of the magnitude found in empirical studies.
Evolving ideas of legume evolution and diversity: a taxonomic perspective on the occurrence of nodulation
Authors: Sprent Janet I.
Published: February 2007

ContentsSummary11I.When and where did legumes evolve?12II.Evolution of legumes and nodulation12III.Taxonomic assessment of nodulation13IV.What triggered the development of nodulation?19V.Nonclassical rhizobia20VI.Conclusions21Acknowledgements23References23
Rates of Cycling Cells in Cryopreserved Valvular Homograft: A Preliminary Study
Authors: Barili Fabio , Dainese Luca , Cheema Faisal H. , Dell'Antonio Giacomo , Topkara Veli K. , Rossoni Giuseppe , Guarino Anna , Micheli Barbara , Doglioni Claudio , Biglioli Paolo , Polvani Gianluca
Published: February 2007

Abstract:  Some investigators claim that the viability of cryopreserved human valvular homograft is necessary for the duration of implanted homograft. In this preliminary study, the percentage of cycling cells in cryopreserved valvular homografts was evaluated with the use of monoclonal Ki‐67 antibody. Three human aortic valves were harvested from multiorgan donors and cryopreserved. Sections of 5 µm in thickness were stained with monoclonal Ki‐67 antibody. The proportion of endothelial cells with Ki‐67 positive nuclei was 1.80 ± 0.20%. No differences in distribution were observed from basal to marginal sites. Few fibroblasts showed Ki‐67‐immunopositivity (0.10 ± 0.06%) while the Ki‐67 immunostaining was 0.80 ± 0.20% in myocytes. Our preliminary study shows that cryopreserved valvular homograft cells are not only viable but they also have the potential to replicate. These data can lead to the hypothesis that valvular cells could actively replicate even after implantation, permitting cellular renewal and regeneration of extracellular matrix's components.
Thunderclap Headache Caused by Minimally Invasive Medical Procedures: Description of 2 Cases
Authors: Devetag Chalaupka Flavio , Caneve Giorgio , Mauri Michela , Zaiotti Giuseppe
Published: February 2007

We report 2 very unusual cases of thunderclap headache complicating minimally invasive medical procedures. In the first case headache developed as the consequence of a pneumocephalus caused by an inadvertent intrathecal puncture during oxygen‐ozone therapy for lumbar disk herniation. The second case involved intracranial hypotension, caused by the persistence of the needle, used for epidural anesthesia, and then penetrated in the subarachnoid space.
Tooth fragment reattachment after retrieval from the lower lip – a case report
Authors: Naudi Antoniella Busuttil , Fung Diane E.
Published: February 2007

Abstract –  The most common traumatic dental injury is the uncomplicated crown fracture of the maxillary central incisor. Various reports have been written about reattachment of the fragment, and literature reviews have cited this technique as the best way of treating these injuries if the fragment is available and properly stored. The case presented here is of a child who sustained an uncomplicated crown fracture with the lost portion of the tooth embedded in his lower lip. This was successfully reattached to the tooth using an acid‐etch and enamel‐bonding resin technique.
Improving asthma discharge management in relation to emergency departments: The ADMIRE project
Authors: Kelly Anne‐Maree , Clooney Megan
Published: February 2007

The present paper describes the process, outcomes and lessons learned from a federally funded, multicentre action research project aimed at improving discharge practices for asthma patients who attend ED and are discharged home. Thirty‐two ED participated and worked locally to improve discharge practices using previously published best‐practice guidelines. Although they achieved some improvements, major barriers to best‐practice discharge outside ED control were identified, including access to GP, hospital policies regarding supply of medications and access to appropriate asthma education. The ED developed some useful tools to assist with improving asthma management that have been compiled as a toolkit and are available online.
Osmotic myelinolysis syndrome after treatment of severe deamino arginine vasopressin‐associated hyponatraemia: Pitfalls in emergency medicine
Authors: Gutenstein Marc
Published: February 2007

Hyponatraemia is among the more common electrolyte abnormalities encountered in the ED. Both the primary disturbance and its correction can result in life‐threatening neurological sequelae. Osmotic myelinolysis syndrome is one such complication and is associated with the rapid correction of hyponatraemia. The present case report describes the mechanism of severe hyponatraemia in a patient taking deamino arginine vasopressin, and the subsequent development of both central pontine and extrapontine myelinolysis after rapid correction of sodium levels. Implications for the emergency management of such patients are discussed.
Second Order Diffraction of Water Waves by a Bottom Mounted Vertical Circular Cylinder and Some Related Numerical Problems
Authors: Yilmaz Oguz
Published: February 2007

A Hankel transformation is used to obtain the second order diffraction solution of vertical cylinder of circular cross section. The improper integral over the free surface is tackled carefully. The singularity at the free surface is overcome effectively using a third order nonlinear transformation. Numerical results for free surface elevations compare well with the published data.
Scanned Three-Dimensional Model Matching and Comparison Algorithms for Manufacturing Applications
Authors: Avagyan Vahram , Zakarian Armen , Mohanty Pravansu
Published: February 2007

In recent years the increased use of 3D scanning hardware has introduced a new type of data to the design and manufacturing field. In many design and manufacturing applications (e.g., part refurbishing or remanufacturing) a scanned 3D model may be provided as an input to a shape matching system to search the database for related or identical models with the purpose of extracting useful information. The introduction of scanned 3D models restricts the use of the CAD-based 3D model search and comparison methods due to significant differences in model representations. The CAD models provide structured and high-level representation of the part features, whereas the scanned 3D models usually come in a polygonal mesh representation, which does not directly reveal engineering features of the part. These differences require new algorithms for comparing the shapes of scanned 3D models, ones that are robust against different scanning technologies and can be adjusted to work with different representations of the models. In this paper, a new approach and algorithms for scanned 3D shape matching and comparison are presented. Given the scanned 3D model as an input the approach first uses general-purpose shape matching methods to identify a small list of likely matches (i.e., candidate models) for more detailed shape comparison. To perform detailed comparison of the shapes each candidate model is geometrically adjusted (i.e., rotated and translated) with the input using one of two new viewpoint algorithms developed in this paper. Once the candidate models are adjusted they are compared to the input to identify the similarities and differences between their shapes. To accomplish this task a new 3D shape matching algorithm is developed. The relevance of the methodology developed in this paper is illustrated with the application of scanned 3D shape matching and comparison algorithms in rapid manufacturing of broken parts.
Experimental Optimization of Extreme Wave Sequences for the Deterministic Analysis of Wave/Structure Interaction
Authors: Clauss Günther F. , Schmittner Christian E.
Published: February 2007

For the deterministic analysis of wave/structure interaction in the sense of cause-reaction chains, and for analyzing structure responses due to special wave sequences (e.g., three sisters phenomenon or other rogue wave groups) methods for the precise generation of tailored wave sequences are required. Applying conventional wave generation methods, the creation of wave trains satisfying given local wave parameters, and the generation of wave groups with predefined characteristics is often difficult or impossible, if sufficient accuracy is required. In this paper we present an optimization approach for the experimental generation of wave sequences with defined characteristics. The method is applied to generate scenarios with a single high wave superimposed to irregular seas. The optimization process is carried out in a small wave tank. The resulting control signal is then transferred to a large wave tank considering the electrical, hydraulic and hydrodynamical response amplitude operators (RAOs) of the respective wave generator in order to investigate wave/structure interaction at a large scale.
FNPF Analysis of Stochastic Experimental Fluid-Structure Interaction Systems
Authors: Yim Solomon C. , Lin Huan , Tanizawa Katsuji
Published: February 2007

A two-dimensional fully nonlinear potential flow model is employed to investigate nonlinear stochastic responses of an experimental fluid-structure interaction system that includes both single-degree-of-freedom surge-only and two-degree-of-freedom surge-heave coupled motions. Sources of nonlinearity include free surface boundary, fluid-structure interaction, and large geometry in the structural restoring force. Random waves performed in the tests include nearly periodic, periodic with band-limited noise, and narrow band. The structural responses observed can be categorized as nearly deterministic (harmonic, sub- and super-harmonic), noisy periodic, and random. Transition phenomena between coexisting response attractors are also identified. An implicit boundary condition upholding the instantaneous equilibrium between the fluid and structure using a mixed Eulerian-Lagrangian method is employed. Numerical model predictions are calibrated and validated via the experimental results under the three types of wave conditions. Extensive simulations are conducted to identify the response characteristics and the effects of random perturbations on nonlinear responses near primary and secondary resonances.
Regulation of Sulfur Assimilation Pathways in
Burkholderia cenocepacia
: Identification of Transcription Factors CysB and SsuR and Their Role in Control of Target Genes
Authors: Iwanicka-Nowicka Roksana , Zielak Agata , Cook Anne M. , Thomas Mark S. , Hryniewicz Monika M.
Published: February 2007

Two genes encoding transcriptional regulators involved in sulfur assimilation pathways in
Burkholderia cenocepacia
strain 715j have been identified and characterized functionally. Knockout mutations in each of the
B. cenocepacia
genes were constructed and introduced into the genome of 715j by allelic replacement. Studies on the utilization of various sulfur sources by 715j and the obtained mutants demonstrated that one of the
B. cenocepacia
regulators, designated CysB, is preferentially involved in the control of sulfate transport and reduction, while the other, designated SsuR, is required for aliphatic sulfonate utilization. Using transcriptional promoter-
lacZ
fusions and DNA-binding experiments, we identified several target promoters for positive control by CysB and/or SsuR—
sbpp
(preceding the
sbp cysT cysW cysA ssuR
cluster),
cysIp
(preceding the
cysI cysD1 cysN cysH cysG
cluster),
cysD2p
(preceding a separate cluster,
cysD2 cysNC
), and
ssuDp
(located upstream of the
ssuDCB
operon)—and we demonstrated overlapping functions of CysB and SsuR at particular promoters. We also demonstrated that the
cysB
gene is negatively controlled by both CysB and SsuR but the
ssuR
gene itself is not significantly regulated as a separate transcription unit. The function of
B. cenocepacia
CysB (in vivo and in vitro) appeared to be independent of the presence of acetylserine, the indispensable coinducer of the CysB regulators of
Escherichia coli
and
Salmonella
. The phylogenetic relationships among members of the “CysB family” in the γ and β subphyla are presented.
Preventing suicide by jumping: the effect of a bridge safety fence
Authors: Pelletier Andrew R
Published: February 2007

Objective:To evaluate the effect of a bridge safety fence in preventing suicide.

Methods:We examined suicides from jumping off the Memorial Bridge in Augusta, Maine, from 1 April 1960 to 31 July 2005. The safety fence was installed during 1983, the mid-point of the study period.

Results:14 suicides from the bridge were identified; all occurred before installation of the safety fence. The number of suicides by jumping from other structures remained unchanged after installation of the fence.

Conclusion:The safety fence was effective in preventing suicides from the bridge. There was no evidence that suicidal individuals sought alternative sites for jumping.
Dietary Folate Intake in Combination with MTHFR C677T Genotype and Promoter Methylation of Tumor Suppressor and DNA Repair Genes in Sporadic Colorectal Adenomas
Authors: van den Donk Maureen , van Engeland Manon , Pellis Linette , Witteman Ben J.M. , Kok Frans J. , Keijer Jaap , Kampman Ellen
Published: February 2007

Methylation of the promoter region of tumor suppressor genes is increasingly recognized to play a role in cancer development through silencing of gene transcription. We examined the associations between dietary folate intake, MTHFR C677T genotype, and promoter methylation of six tumor suppressor and DNA repair genes. Patients with colorectal adenoma (n = 149) and controls (n = 286) with folate intake in the upper or lower tertile with the CC or TT genotype were selected from a case-control study. Methylation-specific PCRs were conducted on colorectal adenoma specimens. The percentages of promoter methylation ranged from 15.7% to 64.2%. In case-case comparisons, folate was inversely associated with promoter methylation, especially among TT homozygotes. Case-control comparisons suggested that folate was not associated with the occurrence of adenomas with promoter methylation, and increased the risk of unmethylated adenomas, especially in TT homozygotes. The interactions between folate and MTHFR genotype were most pronounced for O6-MGMT: compared with CC homozygotes with low folate intake, the adjusted odds ratios (95% confidence interval) of having a methylated O6-MGMT promoter were 3.39 (0.82-13.93) for TT homozygotes with low folate intake and 0.37 (0.11-1.29) for TT homozygotes with high folate intake (P interaction = 0.02); the odds ratios for the occurrence of adenomas without methylation were 0.57 (0.16-2.11) for TT homozygotes with low folate intake and 3.37 (1.17-9.68) for TT homozygotes with high folate intake (P interaction = 0.03). In conclusion, folate intake seems to be inversely associated with promoter methylation in colorectal adenomas in case-case comparisons, and was positively associated with the occurrence of adenomas without promoter methylation in case-control comparisons, especially for TT homozygotes. (Cancer Epidemiol Biomarkers Prev 2007;16(2):327–33)
Mapping of KIT adjacent sequences on canid autosomes and B chromosomes
Authors: Yudkin D.V. , Trifonov V.A. , Kukekova A.V. , Vorobieva N.V. , Rubtsova N.V. , Yang F. , Acland G.M. , Ferguson-Smith M.A. , Graphodatsky A.S.
Published: February 2007

B chromosomes are often considered to be one of the most mysterious elements of karyotypes (Camacho, 2004). It is generally believed that mammalian B chromosomes do not contain any protein coding genes. The discovery of a conserved KIT gene in Canidae B chromosomes has changed this view. Here we performed analysis of sequences surrounding KIT in B chromosomes of the fox and raccoon dog. The presence of the RPL23A pseudogene was shown in canid B chromosomes. The 3′ end fragment of the KDR gene was found in raccoon dog B chromosomes. The size of the B-specific fragment homologous to the autosome fragment was estimated to be a minimum of 480 kbp in both species. The origin and evolution of B chromosomes in Canidae are discussed.
Genome organization of glutamine synthetase genes in rainbow trout (Oncorhynchus mykiss)
Authors: Gharbi K. , Murray B.W. , Moghadam H.K. , Ferguson M.M. , Wright P.A. , Danzmann R.G.
Published: February 2007

Unlike mammals, bony fish appear to possess multiple genes encoding glutamine synthetase (GS), the nitrogen metabolism enzyme responsible for the conversion of glutamate and ammonia into glutamine at the expense of ATP. This study reports on the development of genetic markers for each of the four isoforms identified thus far in rainbow trout (Oncorhynchus mykiss) and their genome localization by linkage mapping. We found that genes coding for GS01, GS02, GS03, and GS04 map to four different linkage groups in the trout genome, namely RT-24, RT-23, RT-08, and RT-13, respectively. Linkage groups RT-23 and RT-13 appear to represent distinct chromosomes sharing duplicated marker regions, which lends further support to the previous suggestion that GS02 and GS04 may be duplicate gene copies that evolved from a whole-genome duplication in the trout ancestor. In contrast, there is at present no further evidence that RT-24 and RT-08 share ancestrally homologous segments and additional genomic studies will be needed to clarify the evolutionary origin of genes coding for GS01 and GS03.
Morphologic Substrates for First-Branch Pulmonary Arterial Hypoplasia in Transposition of the Great Arteries
Authors: Chen Ming-Ren , Wu Shye-Jao , Chiu Ing-Sh , Wang Jou-Kou , Wu Mei-Hwan , Lue Hung-Chi
Published: February 2007

Background: Distal right-sided outflow obstruction remains a problem after arterial switch operation. We studied the anatomical features of the pulmonary trunk (PT) and its branches that are susceptible to right and left pulmonary arterial (RPA and LPA) hypoplasia in transposition of the great arteries (TGA). Methods: One hundred and one angiograms of TGA performed between 1981 and 1996 were viewed, and Polaroid photos were taken at end-systole. The diameters of RPA, LPA, PT, duct, ascending aorta, and angles between PA and PT were measured, and the ductal flow direction was recorded. Results: Forty-eight cases (47.5%) had a PA/PT diameter ratio (both PAs had same size) below 0.49. A smaller PA/PT was significantly related to posterior inclination of the proximal PT [narrower right (r = 0.50, p < 0.00001) and left (r = 0.48, p < 0.00001) PA-PT angle in lateral view] and a larger duct (r = 0.37, p < 0.0001). Eighteen patients had a follow-up angiogram after a mean period of 8.5 months. Those with a closed duct had evident PA growth (n = 12, 0.51 ± 0.09 to 0.74 ± 0.17, p < 0.0001), but four patients with an attenuated duct had no significant change (0.58 ± 0.06 to 0.68 ± 0.08, p = NS), and one with a persistent large duct had even regression of PA/PT (0.36–0.19). The direction of ductal flow was toward the aorta during early systole on cineangiogram. Conclusions: First-branch PA hypoplasia, which is frequently seen in TGA, was related to the right-to-left shunt through a duct resulting in hemodynamic starvation, and to posterior inclination of the proximal PT in this setting. Natural regression of the duct facilitated PA growth.
Accounting for Epistasis in Linkage Analysis of General Pedigrees
Authors: Sung Yun Ju , Wijsman Ellen M.
Published: February 2007

Complex traits are generally believed to be influenced by multiple loci. Identification of loci involved in complex traits is more difficult for interacting than for additive loci. Here we describe an extension of the program lm_twoqtl in the package MORGAN to handle two quantitative trait loci (QTLs) with gene-gene interaction. We investigate whether parametric linkage analysis that accounts for such epistasis improves prospects for linkage detection and accuracy of localization of QTLs. Through use of simulated data we show that analysis that accounts for epistasis provides higher lod scores and better localization than does analysis without epistasis. In addition, we demonstrate that the difference between lod scores in the presence vs. absence of use of an interaction model in analysis is greater in extended than in nuclear pedigrees.