bluuebunny/crossref_metadata_2025 huggingface dataset:
Establishment growth and bud-bank formation in Epilobium angustifolium: the effects of nutrient availability, plant injury, and environmental heterogeneity
Authors: Klimešová Jitka , Pokorná Adéla , Klimeš Leoš
Published: March 2009

Plant establishment is a risky phase of the plant life cycle because juvenile individuals cannot produce seeds and their vegetative regeneration is constrained by a lack of reserve meristems and carbon storage. On the other hand, conditions in the period following establishment, during establishment growth, affect the vegetative regeneration and clonal growth of the plant in the future. Bud-bank formation was studied in a root-sprouting clonal herb Epilobium angustifolium  L. (= Chamaenerion angustifolium (L.) Scop.), a plant with root buds differing in size and number of leaf primordia, during establishment growth. We tested two hypotheses: (i) large and small buds differ in their response to stress and disturbance, and (ii) a heterogeneous soil environment does not affect bud-bank formation. We rejected both hypotheses because (i) the proportion of small buds was about 80% and was not affected by nutrient availability and substrate heterogeneity, and (ii) plants produced more buds per root biomass under conditions of nutrient shortage in both homogeneous and heterogeneous substrates, but the effect was masked by lower root biomass. Thus, bud production for the whole plant was not affected by either nutrient availability or soil heterogeneity and reached 20 to 100 buds per plant.
Developmental comparison of leaf shape variation in threeChamaedoreaspecies
Authors: Nowak Julia , Nowak Adam , Posluszny Usher
Published: March 2009

Compound palm leaf development is unique and consists of two processes. First, the primordial tissue folds through differential growth, forming plications. Second, these plications separate through an abscission-like process, forming leaflets. The second process of leaflet separation allows for the development of compound leaves. The question that this study addresses concerns the development of bifid leaves, as they do not form leaflets but only develop a cleft through an apical incision. The ideal genus to use for this study is Chamaedorea as it includes species with both pinnate and bifid leaves. Chamaedorea fragrans (Ruiz & Pav.) Mart. and Chamaedorea stolonifera H. Wendl. ex Hook. f. were chosen as the species with adult bifid leaves. Although Chamaedorea seifrizii Burret is a pinnate-leaved palm, its juvenile leaves are bifid. Scanning electron microscopy and light microscopy were used to study the development of bifid leaves. Our results indicate that neither of these bifid palms develop separation sites within the lamina, but rather the apical cleft develops through “late leaflet separation” or by an abscission-like process. In contrast, C. seifrizii juvenile leaves exhibit “early leaflet separation” when developing the apical cleft.
Incorporating the effects of interspecific competition and vegetation management treatments in diameter distribution models for Douglas-fir saplings
Authors: Knowe Steven A. , Harrington Timothy B. , Shula Robert G.
Published: March 2009

A parameter recovery procedure for the Weibull distribution function, based on diameter percentiles, was modified to incorporate the effects of interfering vegetation in young Douglas-fir (Pseudotsugamenziesii (Mirb.) Franco var. menziesii) plantations. The applicability of the system was tested by using data from sites in the Coast Ranges of Oregon and Washington and in the Siskiyou Mountains of southwestern Oregon. Four percentiles (0, 25th, 50th, 95th) of the cumulative probability distribution were predicted as functions of quadratic mean diameter and age. In the Siskiyou study, cover and total vegetation control affected quadratic mean diameter and all four percentiles; intensity of the vegetation treatments affected the 0 and 25th percentiles, and the interaction between intensity and timing of treatment affected quadratic mean diameter. In the Coast Ranges study, only quadratic mean diameter was affected by cover of woody vegetation, while quadratic mean diameter and the 25th percentile were significantly affected by total vegetation control. The predicted distributions showed decreasing variance with increasing cover, particularly in the Siskiyou Mountains. In the Coast Ranges study, the coefficient of variation increased with increasing cover, indicating that the variance of stem diameters was affected by average size. On xeric sites in the Siskiyou Mountains, high diameter variability in plots with total vegetation control suggests that interspecific competition may inhibit the expression of microsite variation.
Low levels of genetic diversity in red pine confirmed by random amplified polymorphic DNA markers
Authors: Mosseler A. , Egger K.N. , Hughes G.A.
Published: March 2009

Random amplified polymorphic DNA (RAPD) markers were used to characterize genetic variation in disjunct Newfoundland populations of red pine (Pinusresinosa Ait.) for comparison with individuals from throughout the mainland range of red pine. Red pine demonstrated a largely monomorphic profile for 69 arbitrary oligonucleotide primers. DNA samples from white spruce (Piceaglauca (Moench) Voss) and black spruce (Piceamariana (Mill.) B.S.P.) that were screened together with red pine for 11 oligonucleotide primers showed abundant polymorphisms, confirming the genetic heterogeneity that characterizes these Boreal Zone spruces. Results with RAPD markers correspond with genetic diversity estimates using isozyme gene markers for both spruce species and red pine. RAPD markers provided further confirmation of low levels of genetic variation for a random sample of the red pine genome. A period of between 8000 and 10 000 years of isolation on the island of Newfoundland has resulted in very little detectable genetic differentiation of island populations from mainland populations, and the mainland populations have not recovered from losses of genetic diversity following a hypothesized genetic bottleneck that may have been experienced during glacial episodes of the Holocene. The low levels of genetic variation observed in red pine demonstrate the long time periods required for recovery following a loss of genetic diversity in long-lived, long-generation organisms like trees.
Transience of deer wintering areas
Authors: Boer Arnold H.
Published: March 2009

Fidelity of white-tailed deer (Odocoileusvirginianus) to wintering areas was examined in west-central New Brunswick. Wintering areas were located and mapped during aerial surveys in 1975 and 1987–1989. Of 99 wintering areas identified in 1975, 42 were unoccupied 13 years later. Small wintering areas (<50 ha) were more likely to be unoccupied in the subsequent survey than larger ones (>100 ha). Forest cutting had a profound effect on transience of wintering areas. Small clearcuts within a wintering area increased the likelihood of deer use. Wintering areas that were completely clear-cut were likely to be abandoned.
Pathogenicity of three fungal associates of Hylobiuspales and Pissodesnemorensis (Coleoptera: Curculionidae) to eastern white pine
Authors: Nevill R.J. , Alexander S.A.
Published: March 2009

The pathogenicity of three fungal associates of the pine reproduction weevils, Hylobiuspales (Hbst) and Pissodesnemorensis Germar, to eastern white pine (Pinusstrobus L.) was investigated. Three-year-old eastern white pine seedlings were inoculated with isolates of Leptographiumprocerum (Kendr.) Wingf., Ophiostomapiceae (Munch) Sydow & Sydow, or a Graphium species that produced no perfect state. The inoculations were made by wounding the seedlings and inserting a block of malt extract agar colonized by the respective fungi into the wounds. After 3 months, the wounds of seedlings inoculated with L. procerum were resinous and there were significantly longer lesions in the bark and sapwood than in seedlings inoculated with the other fungi. Based on reisolation from the xylem, both L. procerum and O. piceae colonized the sapwood beyond lesions or any visual discoloration, but the Graphium species did not. These results confirm the pathogenicity of L. procerum and O. piceae and suggests that lesion length alone does not fully characterize colonization by some blue stain fungi.
Deviations from Ultrametricity in Phage Protein Distances
Authors: Wagner Chad , Salamon Anna , Edwards Robert A. , Rohwer Forest , Salamon Peter
Published: March 2009

Distances in biological databases are known not to be ultrametric. Deviations from ultrametricity can however reveal useful features of biodata. In the present study we examine deviations from ultrametricity of the distances between known phage proteins quantified in two senses: (1) the failure of triangles to be isosceles and (2) failure of every point to be the center of any sphere in which it resides. The deviations from these two ultrametric properties undergo qualitative changes as a function of the distance. Below we describe these changes and how they can be observed. We further argue that the distances at which the qualitative changes take place reveal intrinsic scales in the dataset. Such scales are important for choosing threshold values of the distance in various algorithms and reveal natural chunking of the data that can be used to decide clade levels in phage phylogeny.
STABILITY RADII FOR IMPLICIT DIFFERENCE EQUATIONS
Authors: Rodjanadid Benjawan , Nguyen Van Sanh , Nguyen Thu Ha , Nguyen Huu Du
Published: March 2009

This paper is concerned with a formula of stability radii for a linear implicit difference equation (LIDEs for short) varying in time with index-1 under structured parameter perturbations. It is shown that the lp-real and complex stability radii of these systems coincide and they are given by a formula of input-output operators. The result is an extension of a previous result for time-varying ordinary differential equations [7].
Testosterone-augmented contractile responses to α1- and β1-adrenoceptor stimulation are associated with increased activities of RyR, SERCA, and NCX in the heart
Authors: Tsang Sharon , Wong Stanley S. C. , Wu Song , Kravtsov Gennadi M. , Wong Tak-Ming
Published: March 2009

We hypothesized that testosterone at physiological levels enhances cardiac contractile responses to stimulation of both α1- and β1-adrenoceptors by increasing Ca2+ release from the sarcoplasmic reticulum (SR) and speedier removal of Ca2+ from cytosol via Ca2+-regulatory proteins. We first determined the left ventricular developed pressure, velocity of contraction and relaxation, and heart rate in perfused hearts isolated from control rats, orchiectomized rats, and orchiectomized rats without and with testosterone replacement (200 μg/100 g body wt) in the presence of norepinephrine (10−7 M), the α1-adrenoceptor agonist phenylephrine (10−6 M), or the nonselective β-adrenoceptor agonist isoprenaline (10−7 M) in the presence of 5 × 10−7 M ICI-118,551, a β2-adrenoceptor antagonist. Next, we determined the amplitudes of intracellular Ca2+ concentration transients induced by electrical stimulation or caffeine, which represent, respectively, Ca2+ release via the ryanodine receptor (RyR) or releasable Ca2+ in the SR, in ventricular myocytes isolated from the three groups of rats. We also measured 45Ca2+ release via the RyR. We then determined the time to 50% decay of both transients, which represents, respectively, Ca2+ reuptake by sarco(endo)plasmic reticulum Ca2+-ATPase (SERCA) and removal via the sarcolemmal Na+/Ca2+ exchanger (NCX). We correlated Ca2+ removal from the cytosol with activities of SERCA and its regulator phospholamban as well as NCX. The results showed that testosterone at physiological levels enhanced positive inotropic and lusitropic responses to stimulation of α1- and β1-adrenoceptors via the androgen receptor. The increased contractility and speedier relaxation were associated with increased Ca2+ release via the RyR and faster Ca2+ removal out of the cytosol via SERCA and NCX.
Liquid Crystal-Reconfigurable Antenna Concepts for Space Applications at Microwave and Millimeter Waves
Authors: Gaebler A. , Moessinger A. , Goelden F. , Manabe A. , Goebel M. , Follmann R. , Koether D. , Modes C. , Kipka A. , Deckelmann M. , Rabe T. , Schulz B. , Kuchenbecker P. , Lapanik A. , Mueller S. , Haase W. , Jakoby R.
Published: March 2009

Novel approaches of tunable devices for millimeter wave applications based on liquid crystal (LC) are presented. In the first part of the paper, a novel concept of a tunable LC phase shifter realized in Low Temperature Cofired Ceramics technology is shown while the second part of the paper deals with a tunable high-gain antenna based on an LC tunable reflectarray. The reflectarray features continuously beam scanning in between±25∘. Also first investigations on radiation hardness of LCs are carried out, indicating that LCs might be suitable for space applications.
Design of Adaptive Filter Using Jordan/Elman Neural Network in a Typical EMG Signal Noise Removal
Authors: Mankar V. R. , Ghatol A. A.
Published: March 2009

The bioelectric potentials associated with muscle activity constitute the electromyogram (EMG). These EMG signals are low‐frequency and lower‐magnitude signals. In this paper, it is presented that Jordan/Elman neural network can be effectively used for EMG signal noise removal, which is a typical nonlinear multivariable regression problem, as compared with other types of neural networks. Different neural network (NN) models with varying parameters were considered for the design of adaptive neural‐network‐based filter which is a typical SISO system. The performance parameters, that is, MSE, correlation coefficient,N/P, andt, are found to be in the expected range of values.
Plasma Oxidized Low-Density Lipoprotein Levels and Arterial Stiffness in Older Adults
Authors: Brinkley Tina E. , Nicklas Barbara J. , Kanaya Alka M. , Satterfield Suzanne , Lakatta Edward G. , Simonsick Eleanor M. , Sutton-Tyrrell Kim , Kritchevsky Stephen B.
Published: March 2009

Arterial stiffness is a prominent feature of vascular aging and is strongly related to cardiovascular disease. Oxidized low-density lipoprotein (ox-LDL), a key player in the pathogenesis of atherosclerosis, may also play a role in arterial stiffening, but this relationship has not been well studied. Thus, we examined the cross-sectional association between ox-LDL and aortic pulse wave velocity (aPWV), a marker of arterial stiffness, in community-dwelling older adults. Plasma ox-LDL levels and aPWV were measured in 2295 participants (mean age: 74 years; 52% female; 40% black) from the Health, Aging, and Body Composition Study. Mean aPWV significantly increased across tertiles of ox-LDL (tertile 1: 869±376 cm/s; tertile 2: 901±394 cm/s; tertile 3: 938±415 cm/s;
P
=0.002). In multivariate analyses, ox-LDL remained associated with aPWV after adjustment for demographics and traditional cardiovascular disease risk factors (
P
=0.008). After further adjustment for hemoglobin A1c, abdominal visceral fat, antihypertensive and antilipemic medications, and C-reactive protein, the association with ox-LDL was attenuated but remained significant (
P
=0.01). Results were similar when ox-LDL was expressed in absolute (milligrams per deciliter) or relative amounts (percentage of low-density lipoprotein). Moreover, individuals in the highest ox-LDL tertile were 30% to 55% more likely to have high arterial stiffness, defined as aPWV >75th percentile (
P
≤0.02). In conclusion, we found that, among elderly persons, elevated plasma ox-LDL levels were associated with higher arterial stiffness, independent of cardiovascular disease risk factors. These data suggest that ox-LDL may be related to the pathogenesis of arterial stiffness.
Arterial Baroreflex Control of Cardiac Vagal Outflow in Older Individuals Can Be Enhanced by Aerobic Exercise Training
Authors: Deley Gaelle , Picard Glen , Taylor J. Andrew
Published: March 2009

Maintained cardiac vagal function is critical to cardiovascular health in human aging. Aerobic exercise training has been considered an attractive intervention to increase cardiovagal baroreflex function; however, the data are equivocal. Moreover, if regular exercise does reverse the age-related decline in cardiovagal baroreflex function, it is unknown how this might be achieved. Therefore, we assessed the effects of a 6-month aerobic training program on baroreflex gain and its mechanical and neural components in older individuals (5 women and 7 men, aged 55 to 71 years). We assessed baroreflex function using pharmacological pressure changes (bolus nitroprusside followed by bolus phenylephrine) and estimated the integrated gain (ΔR-R interval/Δ systolic blood pressure) and mechanical (Δ diameter/Δ pressure) and neural (ΔR-R interval/Δ diameter) components via measurements of carotid artery diameter in previously sedentary older individuals before and after 6 months of aerobic training. There was a significant 26% increase in baroreflex gain that was directly related to the amount of exercise performed and that was derived mainly from an increase in the neural component of the arterial baroreflex (P<0.05). We did find changes in the mechanical component, but unlike integrated gain and the neural component, these were not related to the magnitude of the exercise stimulus. These results suggest that exercise training can have a powerful effect on cardiovagal baroreflex function, but a sufficient stimulus is necessary to produce the effect. Moreover, adaptations in the afferent-efferent baroreflex control of cardiac vagal outflow may be crucial for the improvement in arterial baroreflex function in older humans.
Relative Humidity Effect on the High-Frequency Attenuation of Water Vapor Flux Measured by a Closed-Path Eddy Covariance System
Authors: Mammarella Ivan , Launiainen Samuli , Gronholm Tiia , Keronen Petri , Pumpanen Jukka , Rannik Üllar , Vesala Timo
Published: March 2009

In this study the high-frequency loss of carbon dioxide (CO2) and water vapor (H2O) fluxes, measured by a closed-path eddy covariance system, were studied, and the related correction factors through the cospectral transfer function method were calculated. As already reported by other studies, it was found that the age of the sampling tube is a relevant factor to consider when estimating the spectral correction of water vapor fluxes. Moreover, a time-dependent relationship between the characteristic time constant (or response time) for water vapor and the ambient relative humidity was disclosed. Such dependence is negligible when the sampling tube is new, but it becomes important already when the tube is only 1 yr old and increases with the age of the tube. With a new sampling tube, the correction of water vapor flux measurements over a Scots pine forest in Hyytiälä, Finland, amounted on average to 7%. After 4 yr the correction increased strongly, ranging from 10%–15% during the summer to 30%–40% in wintertime, when the relative humidity is typically high. For this site the effective correction improved the long-term energy and water balance.

Results suggest that the relative humidity effect on high-frequency loss of water vapor flux should be taken into account and that the effective transfer function should be estimated experimentally at least once per year. On the other hand, this high correction can be avoided by a correct choice and periodic maintenance of the eddy covariance system tube, for example, by cleaning or changing it at least once per year.
Investigation of Microphysical Parameterizations of Snow and Ice in Arctic Clouds during M-PACE through Model–Observation Comparisons
Authors: Solomon Amy , Morrison Hugh , Persson Ola , Shupe Matthew D. , Bao Jian-Wen
Published: March 2009

In this study the Weather Research Forecast model is used with 1-km horizontal grid spacing to investigate the microphysical properties of Arctic mixed-phase stratocumulus. Intensive measurements taken during the Department of Energy Atmospheric Radiation Measurement Program Mixed-Phase Arctic Cloud Experiment (M-PACE) on the North Slope of Alaska, during 9–12 October 2004, are used to verify the microphysical characteristics of the model’s simulation of mixed-phase clouds (MPCs). A series of one- and two-moment bulk microphysical cloud schemes are tested to identify how the treatment of snow and ice affects the maintenance of cloud liquid water at low temperatures. The baseline two-moment simulation results in realistic liquid water paths and in size distributions of snow reasonably similar to observations. With a one-moment simulation for which the size distribution intercept parameter for snow is fixed at values taken from the two-moment simulation, reasonable snow size distributions are again obtained but the cloud liquid water is reduced because the one-moment scheme couples the number concentration to the mixing ratio. The one-moment scheme with the constant snow intercept parameter set to a value typical of midlatitude frontal clouds results in a substantial underprediction of the liquid water path. In the simulations, the number concentration of small ice crystals is found to be underestimated by an order of magnitude. A sensitivity test with the concentration of ice particles larger than 53 μm increased to the observed value results in underprediction of the liquid water path. If ice (not snow) is the primary driver for the depletion of cloud liquid water, then the results of this study suggest that the feedbacks among ice–snow–cloud liquid water may be misrepresented in the model.
Evaluation of Planetary Boundary Layer Parameterizations in Tropical Cyclones by Comparison of In Situ Observations and High-Resolution Simulations of Hurricane Isabel (2003). Part II: Inner-Core Boundary Layer and Eyewall Structure
Authors: Nolan David S. , Stern Daniel P. , Zhang Jun A.
Published: March 2009

This is the second of a two-part study of the representation of the planetary boundary layer (PBL) in high-resolution Weather Research and Forecast Model (WRF) simulations of Hurricane Isabel (2003). The Yonsei University (YSU) PBL parameterization and the Mellor–Yamada–Janjić (MYJ) PBL parameterization are evaluated by direct comparison to in situ data obtained by research aircraft. The numerical model, simulation design, details of the PBL schemes, and the representation of the boundary layer in the outer-core were presented in Part I. This part presents a detailed study of the inner-core PBL, including its axisymmetric and asymmetric structures, and comparisons to analyses of dropsonde data from previous studies.

Although neither PBL scheme was designed specifically for hurricane conditions, their simulated boundary layers are reasonably good representations of the observed boundary layer. Both schemes reproduce certain unique features of the hurricane boundary layer, such as the separate depths of the well-mixed layer and the inflow layer, and the pronounced wind speed maxima near the top of the inflow layer. Modification of the original YSU and MYJ schemes to have ocean roughness lengths more in agreement with recent studies considerably improves the results of both schemes. Even with these improvements, the MYJ consistently produces larger frictional tendencies in the boundary layer than the YSU scheme, leading to a stronger low-level inflow and a stronger azimuthal wind maximum at the top of the boundary layer. For both schemes, differences in the low-level asymmetries between the simulated and observed wind fields appear to be related to eyewall asymmetries forced by environmental wind shear.

The effects of varying horizontal and vertical resolutions are also considered. Increasing the vertical resolution in the PBL results in minor improvements in the inner-core structures. Increasing the horizontal resolution around the eyewall also leads to improved boundary layers, as well as an improvement of the vertical structure of the inner-core wind field.

A summary and discussion of the results of both Parts I and II is provided.
Physical Dating Violence Norms and Behavior Among Sixth-Grade Students From Four U.S. Sites
Authors: Simon Thomas R. , Miller Shari , Gorman-Smith Deborah , Orpinas Pamela , Sullivan Terri
Published: March 2009

Relatively little is known about the prevalence of physical dating violence behaviors and perceived norms about dating violence among early adolescents. A sample of 5,404 sixth-grade students was recruited from four diverse U.S. sites. Over half of the respondents reported that girls hitting their boyfriends was acceptable under certain circumstances (e.g., if made mad or jealous) and more than one in four reported acceptance of boys hitting their girlfriends. Among those reporting that they had a recent boy/ girlfriend, nearly one third of girls (31.5%) and more than one fourth of boys (26.4%) reported being physically aggressive toward this person (e.g., punching, slapping). These data support the need to address the problem of violence within students’ perceived dating relationships in sixth grade or earlier and suggest that preventive interventions should focus on changing norms that support violence between males and females.
Cripping Heterosexuality, Queering Able-Bodiedness: Murderball, Brokeback Mountain and the Contested Masculine Body
Authors: Barounis Cynthia
Published: March 2009

Extending recent scholarship on the intersections between disability studies and queer theory, this article engages in a comparative reading of the films Murderball (dir. Henry Alex Rubin and Dana Adam Shapiro) and Brokeback Mountain (dir. Ang Lee), both released in 2005. The popularity of these two particular films, the author suggests, demonstrates a powerful cultural backlash against those representational histories that have conflated feminization, male homosexuality, and disability. Both films successfully remasculinize their subjects, celebrating queerness and disability as the inevitable product of the hypermasculine body. But, ironically, the rhetoric of masculinity that these narratives share is also the source of their antagonism. The author argues that Murderball's `crip' critique of able-bodiedness relies on repeated heteromasculine performances, while Brokeback Mountain's queer hypermasculinity is deeply invested in an ethic of able-bodiedness. Thus a close reading of both films exposes masculinity as the visual mechanism through which disability and homosexuality are beginning to discipline one another on the contemporary cultural stage.
How I treat symptomatic splenomegaly in patients with myelofibrosis
Authors: Mesa Ruben A.
Published: March 2009

Managing patients with myelofibrosis (MF), either those with primary MF or those whose MF has evolved from antecedent polycythemia vera or essential thrombocythemia, presents many challenges to the hematologist. MF patients have a range of debilitating disease manifestations (eg, massive splenomegaly, cytopenias, constitutional symptoms, and transformation to a treatment-refractory blast phase). Cure is potentially achievable through allogeneic stem cell transplantation; however, this therapy is either inappropriate or not feasible for the majority of patients. Therefore, remaining therapies are palliative but can be of significant value to some MF patients. In particular, management of symptomatic splenomegaly remains one of the most perplexing aspects of MF clinical care. Using medications is the simplest approach for reducing splenomegaly, yet achieving symptomatic response without undue myelosuppression is challenging. Splenectomy or radiotherapy offers benefit, but careful patient selection and close monitoring are required because both have the potential for dangerous adverse effects. Experimental medical therapies, such as JAK2 inhibitors, show promise and may soon play an important role in the management of symptomatic splenomegaly in MF patients. Future care of MF patients, including splenomegaly management, will continue to require the hematologist to select therapeutic options carefully in the context of realistic, achievable goals.
Infectious complications from full extension endobronchial ultrasound transbronchial needle aspiration
Authors: Haas A. R.
Published: March 2009

The development of a convex probe endobronchial ultrasound (CP-EBUS) videobronchoscope to allow real-time transbronchial needle aspiration (TBNA) has been a significant advance in minimally invasive lung cancer staging and diagnosis. Several recent studies have demonstrated CP-EBUS-TBNA to have recovery rivalling that of the current gold standard, cervical mediastinoscopy. These same studies have indicated that the safety of this procedure has no reported complications.

The present case study presents two infectious complications from full extension endobronchial ultrasound transbronchial needle aspiration and discusses possible aetiologies of these infections, as well as implications for future application of this technology.
Influence of comorbid conditions on asthma
Authors: Boulet L-P.
Published: March 2009

Various conditions such as rhinosinusitis, gastro-oesophageal reflux disease, psychological disturbances, chronic infections and obstructive sleep apnoea are often observed in asthmatic patients and may affect asthma control and outcomes. These comorbidities may change the asthma phenotype, be part of the same pathophysiological process, act as confounding factors in the diagnosis or assessment of control of asthma, and/or result from specific environmental exposures. The influences of these conditions on asthma are variable and for many of them still uncertain; nevertheless, they may alter asthma responses to current therapy. A systematic evaluation and an appropriate treatment of asthma-associated comorbid conditions should be part of asthma management, particularly for severe disease. With regard to clinical research, associated conditions may influence the results of trials and should be taken into account in the subjects' inclusion criteria and analysis of data.
An improved ontological representation of dendritic cells as a paradigm for all cell types
Authors: Masci Anna Maria , Arighi Cecilia N , Diehl Alexander D , Lieberman Anne E , Mungall Chris , Scheuermann Richard H , Smith Barry , Cowell Lindsay G
Published: March 2009

Background

Recent increases in the volume and diversity of life science data and information and an increasing emphasis on data sharing and interoperability have resulted in the creation of a large number of biological ontologies, including the Cell Ontology (CL), designed to provide a standardized representation of cell types for data annotation. Ontologies have been shown to have significant benefits for computational analyses of large data sets and for automated reasoning applications, leading to organized attempts to improve the structure and formal rigor of ontologies to better support computation. Currently, the CL employs multiple is_a relations, defining cell types in terms of histological, functional, and lineage properties, and the majority of definitions are written with sufficient generality to hold across multiple species. This approach limits the CL's utility for computation and for cross-species data integration.

Results

To enhance the CL's utility for computational analyses, we developed a method for the ontological representation of cells and applied this method to develop a dendritic cell ontology (DC-CL). DC-CL subtypes are delineated on the basis of surface protein expression, systematically including both species-general and species-specific types and optimizing DC-CL for the analysis of flow cytometry data. We avoid multiple uses of is_a by linking DC-CL terms to terms in other ontologies via additional, formally defined relations such as has_function.

Conclusion

This approach brings benefits in the form of increased accuracy, support for reasoning, and interoperability with other ontology resources. Accordingly, we propose our method as a general strategy for the ontological representation of cells. DC-CL is available from http://www.obofoundry.org.
Human parainfluenza virus type 2 (HPIV2) induced host ADAM8 expression in human salivary adenocarcinoma cell line (HSY) during cell fusion
Authors: Ma Guo-Feng , Miettinen Simo , Porola Pauliina , Hedman Klaus , Salo Jari , Konttinen Yrjö T
Published: March 2009

Background

The aim of the study was to investigate expression of ADAMs (A Disintegrin and A Metalloproteinase) of host cell origin during cell-cell fusion induced by human parainfluenza virus type 2 (HPIV2).

Results

Induction of host cell ADAM9 was observed in GMK cells, but the applicability of this model was restricted by lack of cross-reactivity of the anti-human ADAM8 antibodies with the corresponding green monkey antigens. HSG cells were not susceptible to HPIV2 virus infection. In contrast, in human parotid gland HSY cells, a natural host cell for paramyxoviruses, HPIV2 induced ADAM8 expression. ADAM8 staining increased dramatically over time from 7.9 ± 3% at zero hours to 99.2 ± 0.8% at 72 hours (p = 0.0001). Without HPIV2 the corresponding percentages were only 7.7% and 8.8%. Moreover, ADAM8 positive cells formed bi- (16.2%) and multinuclear cells (3.5%) on day one and the corresponding percentages on day three were 15.6% for binuclear and 57.2% for multinuclear cells.

Conclusion

ADAM8, well recognized for participation in cell-to-cell fusion especially in osteoclast formation, is up-regulated upon formation of multinuclear giant cells after HPIV2 induction in HSY cells. The virus-HSY cell system provides a novel experimental model for study of the molecular mechanism of cell fusion events.
Reconstructing the ubiquitin network - cross-talk with other systems and identification of novel functions
Authors: Venancio Thiago M , Balaji S , Iyer Lakshminarayan M , Aravind L
Published: March 2009

Background

The ubiquitin system (Ub-system) can be defined as the ensemble of components including Ub/ubiquitin-like proteins, their conjugation and deconjugation apparatus, binding partners and the proteasomal system. While several studies have concentrated on structure-function relationships and evolution of individual components of the Ub-system, a study of the system as a whole is largely lacking.

Results

Using numerous genome-scale datasets, we assemble for the first time a comprehensive reconstruction of the budding yeast Ub-system, revealing static and dynamic properties. We devised two novel representations, the rank plot to understand the functional diversification of different components and the clique-specific point-wise mutual-information network to identify significant interactions in the Ub-system.

Conclusions

Using these representations, evidence is provided for the functional diversification of components such as SUMO-dependent Ub-ligases. We also identify novel components of SCF (Skp1-cullin-F-box)-dependent complexes, receptors in the ERAD (endoplasmic reticulum associated degradation) system and a key role for Sus1 in coordinating multiple Ub-related processes in chromatin dynamics. We present evidence for a major impact of the Ub-system on large parts of the proteome via its interaction with the transcription regulatory network. Furthermore, the dynamics of the Ub-network suggests that Ub and SUMO modifications might function cooperatively with transcription control in regulating cell-cycle-stage-specific complexes and in reinforcing periodicities in gene expression. Combined with evolutionary information, the structure of this network helps in understanding the lineage-specific expansion of SCF complexes with a potential role in pathogen response and the origin of the ERAD and ESCRT systems.
Gender differences in the association between childhood abuse and psychosis
Authors: Fisher Helen , Morgan Craig , Dazzan Paola , Craig Thomas K. , Morgan Kevin , Hutchinson Gerard , Jones Peter B. , Doody Gillian A. , Pariante Carmine , McGuffin Peter , Murray Robin M. , Leff Julian , Fearon Paul
Published: March 2009

Background

Studies demonstrating an association between childhood trauma and psychosis in adulthood have not systematically explored gender differences.

Aims

To investigate gender differences in the prevalence of childhood sexual and physical abuse among people with psychosis in comparison with healthy controls.

Method

The Childhood Experiences of Care and Abuse Questionnaire was completed to elicit experiences of sexual and physical abuse during childhood in first-episode psychosis cases and population-based controls.

Results

Among women, those in the cases group were twice as likely to report either physical or sexual abuse compared with controls following adjustment for all confounders. In particular, the effect of physical abuse in women was stronger and more robust than that for sexual abuse. A similar trend was found for psychotic-like experiences in the female control group. No association was found in men.

Conclusions

Reports of severe childhood physical or sexual abuse were associated with psychosis in women but not in men.
Mental health implications of detaining asylum seekers: systematic review
Authors: Robjant Katy , Hassan Rita , Katona Cornelius
Published: March 2009

Background

The number of asylum seekers, refugees and internally displaced people worldwide is rising. Western countries are using increasingly restrictive policies, including the detention of asylum seekers, and there is concern that this is harmful.

Aims

To investigate mental health outcomes among adult, child and adolescent immigration detainees.

Method

A systematic review was conducted of studies investigating the impact of immigration detention on the mental health of children, adolescents and adults, identified by a systematic search of databases and a supplementary manual search of references.

Results

Ten studies were identified. All reported high levels of mental health problems in detainees. Anxiety, depression and posttraumatic stress disorder were commonly reported, as were self-harm and suicidal ideation. Time in detention was positively associated with severity of distress. There is evidence for an initial improvement in mental health occurring subsequent to release, although longitudinal results have shown that the negative impact of detention persists.

Conclusions

This area of research is in its infancy and studies are limited by methodological constraints. Findings consistently report high levels of mental health problems among detainees. There is some evidence to suggest an independent adverse effect of detention on mental health.
Intrauterine testosterone exposure and risk for disordered eating
Authors: Baker Jessica H. , Lichtenstein Paul , Kendler Kenneth S.
Published: March 2009

Previous research has suggested that prenatal testosterone exposure masculinises disordered eating by comparing opposite- and same-gender twins. The objective of the current study is to replicate this finding using a sample of 439 identical and 213 fraternal females, 461 identical and 344 fraternal males, and 361 males and 371 females from opposite-gender twin pairs. Disordered eating was compared across twin types using the Eating Disorder Inventory–2. Inconsistent with previous findings, a main effect of co-twin gender was not found. Our results raise questions about the validity of prior evidence of the impact of prenatal testosterone exposure on patterns of disordered eating.
Molecular Response to Cetuximab and Efficacy of Preoperative Cetuximab-Based Chemoradiation in Rectal Cancer
Authors: Debucquoy Annelies , Haustermans Karin , Daemen Anneleen , Aydin Selda , Libbrecht Louis , Gevaert Olivier , De Moor Bart , Tejpar Sabine , McBride William H. , Penninckx Freddy , Scalliet Pierre , Stroh Christopher , Vlassak Soetkin , Sempoux Christine , Machiels Jean-Pascal
Published: March 2009

Purpose

To characterize the molecular pathways activated or inhibited by cetuximab when combined with chemoradiotherapy (CRT) in rectal cancer and to identify molecular profiles and biomarkers that might improve patient selection for such treatments.

Patients and Methods

Forty-one patients with rectal cancer (T3-4 and/or N+) received preoperative radiotherapy (1.8 Gy, 5 days/wk, 45 Gy) in combination with capecitabine and cetuximab (400 mg/m2 as initial dose 1 week before CRT followed by 250 mg/m2 /wk for 5 weeks). Biopsies and plasma samples were taken before treatment, after cetuximab but before CRT, and at the time of surgery. Proteomics and microarrays were used to monitor the molecular response to cetuximab and to identify profiles and biomarkers to predict treatment efficacy.

Results

Cetuximab on its own downregulated genes involved in proliferation and invasion and upregulated inflammatory gene expression, with 16 genes being significantly influenced in microarray analysis. The decrease in proliferation was confirmed by immunohistochemistry for Ki67 (P = .01) and was accompanied by an increase in transforming growth factor-α in plasma samples (P < .001). Disease-free survival (DFS) was better in patients if epidermal growth factor receptor expression was upregulated in the tumor after the initial cetuximab dose (P = .02) and when fibro-inflammatory changes were present in the surgical specimen (P = .03). Microarray and proteomic profiles were predictive of DFS.

Conclusion

Our study showed that a single dose of cetuximab has a significant impact on the expression of genes involved in tumor proliferation and inflammation. We identified potential biomarkers that might predict response to cetuximab-based CRT.
Prospective Risk-Adjusted [18F]Fluorodeoxyglucose Positron Emission Tomography and Computed Tomography Assessment of Radiation Response in Head and Neck Cancer
Authors: Moeller Benjamin J. , Rana Vishal , Cannon Blake A. , Williams Michelle D. , Sturgis Erich M. , Ginsberg Lawrence E. , Macapinlac Homer A. , Lee J. Jack , Ang K. Kian , Chao K.S. Clifford , Chronowski Gregory M. , Frank Steven J. , Morrison William H. , Rosenthal David I. , Weber Randal S. , Garden Adam S. , Lippman Scott M. , Schwartz David L.
Published: March 2009

Purpose

[18F]Fluorodeoxyglucose positron emission tomography (FDG-PET)/computed tomography (CT) imaging may improve assessment of radiation response in patients with head and neck cancer, but it is not yet known for which patients this is most useful. We conducted a prospective trial to identify patient populations likely to benefit from the addition of functional imaging to the assessment of radiotherapy response.

Patients and Methods

Ninety-eight patients with locally advanced cancer of the oropharynx, larynx, or hypopharynx were prospectively enrolled and treated with primary radiotherapy, with or without chemotherapy. Patients underwent FDG-PET/CT and contrast-enhanced CT imaging 8 weeks after completion of treatment. Functional and anatomic imaging response was correlated with clinical and pathologic response. Imaging accuracy was then compared between imaging modalities.

Results

Although postradiation maximum standard uptake values were significantly higher in nonresponders compared with responders, the positive and negative predictive values of FDG-PET/CT scanning were similar to those for CT alone in the unselected study population. Subset analyses revealed that FDG-PET/CT outperformed CT alone in response assessment for patients at high risk for treatment failure (those with human papillomavirus [HPV] –negative disease, nonoropharyngeal primaries, or history of tobacco use). No benefit to FDG-PET/CT was seen for low-risk patients lacking these features.

Conclusion

These data do not support the broad application of FDG-PET/CT for radiation response assessment in unselected head and neck cancer patients. However, FDG-PET/CT may be the imaging modality of choice for patients with highest risk disease, particularly those with HPV-negative tumors. Optimal timing of FDG-PET/CT imaging after radiotherapy merits further investigation.
Newer Antidepressants and Gabapentin for Hot Flashes: An Individual Patient Pooled Analysis
Authors: Loprinzi Charles L. , Sloan Jeff , Stearns Vered , Slack Rebecca , Iyengar Malini , Diekmann Brent , Kimmick Gretchen , Lovato James , Gordon Paul , Pandya Kishan , Guttuso Thomas , Barton Debra , Novotny Paul
Published: March 2009

Purpose

Nonhormonal treatment options have been investigated as treatments for hot flashes, a major clinical problem in many women. Starting in 2000, a series of 10 individual double-blind placebo-controlled studies has evaluated newer antidepressants and gabapentin for treating hot flashes. This current project was developed to conduct an individual patient pooled analysis of the data from these published clinical trials.

Patients and Methods

Individual patient data were collected from the various study investigators who published their study results between 2000 and 2007. Between-study heterogeneity for study characteristics and patient populations was tested via χ2 tests before a pooled analysis. The primary end point, the change in hot flash activity from baseline to week 4, for each agent was calculated via both weighted and unweighted approaches, using the size of the study as the weight. Basic summary statistics were produced for hot flash score and frequency using the following three statistics: raw change, percent reduction, and whether or not a 50% reduction was achieved.

Results

This study included seven trials of newer antidepressants and three trials of gabapentin. The optimal doses (defined by individual study results) of the newer antidepressants paroxetine, venlafaxine, fluoxetine, and sertraline decreased hot flash scores by 41%, 33%, 13%, and 3% to 18% compared with the corresponding placebo arms, respectively. The three gabapentin trials decreased hot flashes by 35% to 38% compared with the corresponding placebo arms.

Conclusion

Some newer antidepressants and gabapentin, within 4 weeks of therapy initiation, decrease hot flashes more than placebo.
A new approach to the calculation of Euler work for centrifugal fan impellers
Authors: Tan J J , Qi D T , Luo T F
Published: March 2009

In a conventional one-dimensional scheme design of centrifugal fans and compressors, it is assumed that there is no flow prewhirl at the impeller inlet when the inlet guide vane is absent. However, many experiments have proved that the flow prewhirl does exist at the inlet of centrifugal impellers. This results in an error in the design of centrifugal fans and compressors. In this study a new method is presented to calculate the Euler work of centrifugal impellers considering the presence of an inlet flow prewhirl in the case without the inlet guide vane. Stodola's approach dealing with the slip velocity at the impeller outlet is applied to the impeller inlet. A new formula for Euler work calculation is deduced to evaluate the effect of the inlet prewhirl. The new formula has been applied to 33 industrial centrifugal fans and the calculated results have been compared with the experimental data of these fans. The comparison shows that the new formula is more accurate in most cases than the original formula without consideration of the inlet flow prewhirl, and the accuracy has been improved by more than 10 per cent on average. The aim of this study is to improve the accuracy of the one-dimensional scheme design of centrifugal fans and to provide a reference for a similar research.
The prevalence of hallux valgus and its association with foot pain and function in a rural Korean community
Authors: Cho N. H. , Kim S. , Kwon D.-J. , Kim H. A.
Published: March 2009

There are few data available regarding the association between hallux valgus and pain or functional limitation. We determined the prevalence of hallux valgus in a rural Korean population aged between 40 and 69 years, and its association with pain and function. A total of 563 subjects was examined using the foot health status questionnaire, the Short Form-36 questionnaire and weight-bearing anteroposterior radiographs.

Hallux valgus was present in 364 subjects (64.7%). It did not significantly correlate with age and was more common in women. Of the 364 subjects, 48 (13.2%) had moderate or greater deformity, defined as a hallux valgus angle > 25°. This was significantly associated with pain, worse function and worse foot health. The putative risk factors associated with painful hallux valgus were female gender, low educational attainment and the presence of pain in the knee.