bluuebunny/crossref_metadata_2025 huggingface dataset:
Elevations in Troponin I After Percutaneous Coronary Interventions Are Associated With Abnormal Tissue-Level Perfusion in High-Risk Patients With Non–ST-Segment–Elevation Acute Coronary Syndromes
Authors: Bolognese Leonardo , Ducci Kenneth , Angioli Paolo , Falsini Giovanni , Liistro Francesco , Baldassarre Silvia , Burali Antonio
Published: September 2004

Background—

In the setting of non–ST-segment–elevation (NSTE) acute coronary syndromes (ACS), the pathophysiological mechanisms underlying post–percutaneous coronary intervention (PCI) cardiac troponin I (cTnI) elevation remain unclear.

Methods and Results—

We evaluated the relationship between troponin elevation and tissue-level perfusion using the TIMI flow grade, corrected TIMI frame count, TIMI myocardial perfusion grade (TMPG), and myocardial contrast enhancement by intracoronary myocardial contrast echocardiography (MCE) before and immediately after PCI performed within 24 to 48 hours of hospital admission in 42 high-risk (angina at rest, unequivocal ST-segment depression, and cTnI elevation) patients with NSTE-ACS. All patients were treated with glycoprotein IIb/IIIa inhibitors (27 with tirofiban and 15 with abciximab) and had successful PCI. Fourteen patients had a postprocedural cTnI elevation, whereas 28 did not. TMPG 0/1 after PCI was observed more frequently in patients with postprocedural cTnI elevation (43% versus 7%;
P
<0.02). cTnI levels were higher among patients with TMPG 0/1 versus patients with TMPG 2/3 (5.3±2.7 versus 1.5±1.3 ng/mL;
P
<0.0001). Patients with postprocedural cTnI elevation also presented a significantly lower number of perfused segments at MCE (59% versus 81%;
P
=0.02) as well as a lower MCE score index (0.65±0.38 versus 0.89±0.21;
P
<0.02).

Conclusions—

Postprocedural cTnI elevation in high-risk patients with NSTE-ACS is associated with an abnormal tissue-level perfusion.
Understanding the Yarowsky Algorithm
Authors: Abney Steven
Published: September 2004

Many problems in computational linguistics are well suited for bootstrapping (semisupervised learning) techniques. The Yarowsky algorithm is a well-known bootstrapping algorithm, but it is not mathematically well understood. This article analyzes it as optimizing an objective function. More specifically, a number of variants of the Yarowsky algorithm (though not the original algorithm itself) are shown to optimize either likelihood or a closely related objective function K.
Links between the Linguistic Ability and International Experience of Export Managers and their Export Marketing Intelligence Behaviour
Authors: Williams Jasmine E. M. , Chaston Ian
Published: September 2004

This article presents the results of qualitative and quantitative investigations into the international background and language skills of export managers in small and medium-sized enterprises (SMEs), and their export marketing intelligence behaviour. In doing so, it attempts to shed light on the relationship between these two sets of factors, both of which have been identified as affecting export performance. At the quantitative stage, non-parametric statistical analyses were used to identify profiles of export managers’ information gathering, information use and decision-making activities, based on their linguistic ability, their experience of working or living overseas and their exporting experience. The research provides guidelines for SME employers who wish to match export managers’ market intelligence styles with their firms’ overseas market objectives.
Applicability of Attractor Control Techniques for a Particle Conveyed by a Propagating Wave
Authors: Ragulskis M. , Koizumi K.
Published: September 2004

The governing equations of motion describing the dynamics of a conveyed particle by a propagating surface wave are derived. Although the problem may look rather primitive, it holds considerable complications first of all due to the fact that the shape of the surface cannot be described explicitly Special forward and reverse time marching numerical techniques, incorporating the solution of nonlinear algebraic equations in every time step, are developed for time integration of derived differential equations. It is shown that the described system possesses numerous nonlinear features such as sensitivity to initial conditions. cocxistint, attractors. This fact builds the foundation for the potential applicability of attractor control techniques based on small external impulses.
Adaptive Stabilization of Linear Second-Order Systems with Bounded Time-Varying Coefficients
Authors: Roup Alexander V. , Bernstein Dennis S.
Published: September 2004

We consider adaptive stabilization for a class of linear time-varying second-order systems. Interpreting the system states as position and velocity, the system is assumed to have unknown, non-paranetric, bounded time-varying damping and stiffness coefficients. The coefficient bounds need not be known to implement the adaptive controller. Lyapunov methods are used to prove global convergence of the system states. For illustration, the controller is used to stabilize several example systems.
A Fracture Criterion of "Barenblatt" Type for an Intersonic Shear Crack
Authors: Antipov Y. A. , Obrezanova O. , Willis J. R.
Published: September 2004

Steady-state intersonic propagation of a shear crack is considered, with the admission of cohesion across the crack faces. The asymptotic limit of "small-scale cohesion". which occurs when the magmitude of the cohesive stress far exceeds that of the applied stress, is developed explicitly to obtain a criterion ot "Barenblatt" type. The application of this criterion requires only the calculation of the "applied" stress intensity coefficient with cohesion disregarded: an equation of motion follows by equating this coefficient to a modulus of cohesion" which depends on the cohesive model that is employed. An explicit formula for the "modulus of cohesion" is given for the special case of a cohesive zone of Dugdale type.
Second-Order Homogenization Estimates Incorporating Field Fluctuations in Finite Elasticity
Authors: Lopez-Pamies O. , Ponte Castañeda P.
Published: September 2004

This paper presents the applicaition of a recently proposed "second-order"homogenization method (Ponte Castañeda 2002; J. Mech. Phys. Solids 50, 737) to the estimation of the effective behavior of hypetrelastic composites subjected to finite deformations. The key idea is to introduce an optimally chosen "linear comparison composite" which can then be used to convert available homogenization estimates bor linear composites directly into new estimates for the nonlinear hyperelastic composites. More precisely, the method makes use of "generalized" secant moduli that are intermediate between the standard "secant" and "tangent" moduli of the nonlinear phases, and that depend not only on the averages, or first moments of the fields in the phases, but also on the second moments of the field fluctuations, or phase covariance tensors. The use of the method is illustrated in the context of carbon-black-filled, and fiber-reinforced elastomers, and estimates analogous to the well-known Hashin=-Shtrikman and self-consistent estimates for linear-elastic composites are generated. The new estimates are compared with corresponding estimates using an earlier version of the method (Ponte Castañeda and Tiberio 2000; J Mech. Phys. Solids 48, 1389) neglecting the use of fluctuations, and the new results are found to be superior. In particular, the new estimates, unlike the earlier ones, are found to satisfy a rigorous bound, and to give more realistic predictions in the important limit of incompressible behavior.
Identifying the Mental Health Needs of Looked after Young People
Authors: Mount Jenny , Lister Andrew , Bennun Ian
Published: September 2004

Fifty looked after young people and their carers were interviewed to elicit whether, intuitively, they considered the young person to have a mental health problem and when they would seek professional help. This intuitive judgement of need was compared with responses to a mental health screen, and specific depression and conduct disorder scales. The results suggest that carers perceived 70% of young people to have significant mental health need; high levels of depression (28%) and conduct disorder (34%) were also found. Carers were four times more likely to identify mental health needs, both intuitively and on the mental health screen, than young people did themselves. Two-thirds of carers were intuitively accurate in identifying mental health need in their young people, although fewer than half of those identified as having high needs were being seen by a mental health specialist. Of concern, 23% of carers failed to identify needs, subsequently identified by the mental health screen. Perceived familial burden predicted a high mental health needs screen outcome. Given the established risks to mental health for this population of young people, the utility of a systematic mental health screen is discussed.
A Home-Treatment System in Child and Adolescent Psychiatry
Authors: Erkolahti Ritva , Lahtinen Elina , Ilonen Tuula
Published: September 2004

This article describes a working model in which an evaluation and intervention programme for child and adolescent psychiatric patients and their families is conducted in the family's home. To improve services for child psychiatric patients, a home-based evaluation, guidance and treatment programme was started in Satakunta Hospital District in 1995. Further goals were to improve connections between the child's environment and social network, to reduce the long waiting list for treatment and to offer an alternative to in-patient care. Conducting psychiatric care at home enables the clinical team to correct problematic forms of interaction in an effective and constructive manner. The whole family works with staff members, creating a strong therapeutic relationship and opportunities for therapeutic reflection. Parents' motivation to improve their parenting abilities is increased. The main benefits are comprehensiveness and a direct effect on the family's daily life. The largest numbers of patients, in both the home treatment and in-patient programmes (31 and 39%), were diagnosed with affective disorders. The second largest group in the home-treatment programme (18%) was diagnosed with developmental and organic disorders, and in the in-patient programme (33%) with conduct disorders. The number of patients in the home-treatment programme has steadily increased. By 2000,26% of patients were treated at home.
Non-Attendance at Initial Out-Patient Appointments at a Hospital-Based Child Psychiatric Clinic
Authors: Minty Brian , Anderson Cameron
Published: September 2004

Non-attendance at initial Child and Adolescent Mental Health Services out-patient appointments has been a major problem for staff and (indirectly) for families. The findings presented in this article are, to some extent, in line with previous studies of non-attendance, and to some extent go beyond them. The article organizes findings from previous studies and our own results into four categories: demographic, referral related, system (clinic) related and personal or family related. It focuses on demographic and system-related factors, and reports several significant findings in these areas. Making contact with the family prior to the date of the appointment seems to be a very potent factor in avoiding non-attendance, particularly when the family are asked to confirm whether they will be attending. Demographic factors such as the possession of a car, poverty, single parenthood, and having to care for other dependent relatives are significantly related to attendance rates, either positively or negatively. The quality of the referral letter seemed in some circumstances to be highly related to attendance. Suggestions are made on how to reach out to families that find it hard to attend initial appointments.
Modulation of cord blood CD8+ T-cell effector differentiation by TGF-β1 and 4-1BB costimulation
Authors: Kim Young-June , Stringfield Teresa M. , Chen Yan , Broxmeyer Hal E.
Published: September 2004

Transforming growth factor-β1 (TGF-β1), an immunosuppressive cytokine, inhibits cytotoxic T cell (CTL) immune responses. In contrast, 4-1BB (CD137), a costimulatory molecule in the tumor necrosis factor (TNF) receptor family, amplifies CTL-mediated antitumor immune responses. We investigated whether TGF-β1 responses could be reversed by 4-1BB costimulation during in vitro differentiation of naive CD8+ T cells into effector CTL cells. TGF-β1 potently suppressed CTL differentiation of human cord blood naive CD8+ T cells as determined by reduced induction of characteristic phenotypes of effector cells and cytotoxic activity. TGF-β1-mediated suppression of CTL differentiation was abrogated by 4-1BB costimulation but not by CD28 or another member in the TNF receptor family, CD30. 4-1BB costimulation suppressed Smad2 phosphorylation induced by TGF-β1, suggesting that 4-1BB effects were at the level of TGF-β1 signaling. 4-1BB effects on the TGF-β1-mediated suppression were enhanced by interleukin 12 (IL-12) but counteracted by IL-4; 4-1BB expression was up- or down-regulated, respectively, by IL-12 and IL-4. IL-4 was more dominant than IL-12 when both cytokines were present during 4-1BB costimulation in the presence of TGF-β1. This indicates critical roles for IL-4 and IL-12 in regulating 4-1BB effects on TGF-β1-mediated suppression. (Blood. 2005;105:274-281)
The Jab1/COP9 signalosome subcomplex is a downstream mediator of Bcr-Abl kinase activity and facilitates cell-cycle progression
Authors: Tomoda Kiichiro , Kato Jun-ya , Tatsumi Eiji , Takahashi Takayuki , Matsuo Yoshinobu , Yoneda-Kato Noriko
Published: September 2004

Jab1 is a multifunctional protein associated with the signaling pathway, cell-cycle regulation, and development, and acts as a key subunit of COP9 signalosome (CSN). Jab1 promotes degradation of the cyclin-dependent kinase inhibitor p27Kip1 by transportation from the nucleus to the cytoplasm. However, there has been no clear evidence for whether and how Jab1 contributes to malignant transformation in human cancers. Here we show that Bcr-Abl tyrosine kinase facilitates the down-regulation of p27 by modulating complex formation of Jab1/CSN through the mitogen-activated protein (MAP) kinase and phosphatidylinositol 3 (PI3) kinase signaling pathways. Nearly half of the chronic myelogenous leukemia cell lines and the murine hematopoietic precursor cells expressing Bcr-Abl exhibited a marked increase in the small loose Jab1 complex located in the cytoplasm. Inhibition of Bcr-Abl kinase by STI571 induced G1 arrest and caused a recovery of the p27 level with reduction of the small Jab1 complex from the cytoplasm. Either blockade of the MAP kinase and PI3 kinase pathways by specific inhibitors or Jab1 knockdown by small interfering RNA (siRNA) prevented p27 down-regulation as well as formation of the small complex. Thus, regulation of p27 via modulation of the Jab1 subcomplex is a novel mechanism whereby Bcr-Abl oncogenic signals accelerate abnormal cell proliferation.
Tibolone Activates Nitric Oxide Synthesis in Human Endothelial Cells
Authors: Simoncini Tommaso , Mannella Paolo , Fornari Letizia , Caruso Antonella , Varone Gaetano , Garibaldi Silvia , Genazzani Andrea R.
Published: September 2004

After the unexpected findings of the Women’s Health Initiative trial, indicating that traditional cardiovascular risk markers fail to predict the effects of hormone replacement therapy, it is of interest to characterize how steroids act on vascular cells. This is particularly important for tissue-specific drugs such as tibolone, whose actions may differ from other preparations. Because nitric oxide (NO) is a key regulator of vascular tone and atherogenesis, we studied its regulation by tibolone and its metabolites on human endothelial cells. Tibolone and its estrogenic metabolites (3α- and 3β-OH tibolone) activate NO synthesis by recruiting functional estrogen receptors, whereas the progestogenic/androgenic metabolite (Δ4 isomer) has no effect. During prolonged exposures, tibolone and the estrogenic compounds enhance the expression of endothelial NO synthase (eNOS). In addition, tibolone is able to induce rapid activation of eNOS, leading to rapid increases in the release of NO. Relevant for its clinical effects, the sulfated metabolites of tibolone are also effective in activating eNOS. Different from estrogen, rapid activation of eNOS does not rely on recruitment of phosphatidylinositol-3 kinase but rather on MAPK-dependent cascades. These results help to understand the mechanisms of action of tibolone on the cardiovascular system and have relevant clinical implications.
Atomization characteristics and prediction accuracies of hybrid break-up models for a gasoline direct injection spray
Authors: Lee Chang Sik , Kim Hyung Jun , Park Sung Wook
Published: September 2004

The purpose of this study is to investigate the prediction accuracy of hybrid models on the atomization processes of fuel sprays injected from a gasoline direct injection system. In order to analyze the prediction characteristics of hybrid schemes, various hybrid models for the primary and secondary break-ups of high-pressure gasoline spray are formulated by combining two different models. For the primary break-up, the LISA and WAVE break-up models are used, whereas the TAB, DDB, and RT models are utilized for the secondary break-up, considering the break-up mechanism of each break-up model. Therefore, six hybrid models are applied to the simulation of the atomization process and the prediction accuracies of the break-up processes are evaluated by comparing them with the experimental results. To obtain experimental results for comparison with the predicted ones, the local Sauter mean diameter and axial mean velocity are measured by using a phase Doppler particle analyzer. Also, the spray visualization system is utilized to analyze the process of spray development and spray-tip penetration.

It is revealed that all hybrid models show reasonable agreement with the experimental results of spray-tip penetration. On the other hand, different accuracies are shown in the distributions of local SMD and axial mean velocity.
Experimental study of local temperature distributions in rotary blade couplings of four-wheel-drive vehicles with circumferentially ribbed turbulators
Authors: Tzeng S C , Jou R Y , Liou J H
Published: September 2004

This work experimentally investigates temperature distributions of RBCs (rotating blade couplings) using circumferentially installed ribbed turbulators in real-time 4WD (four-wheel-drive) vehicles. Three types of circumferential rib turbulators are designed and installed in the RBC's inner rotating cylinder. These add to the area over which heat is transferred and prevent the generation of Taylor vorticity. A test rig is designed to make the key dimensionless parameters closely approximate the operating conditions of a real 4WD vehicle. The local temperature distributions in the axial and circumferential directions of a RBC with circumferentially ribbed turbulators, were measured and compared with those in smooth walls. Under the experimental conditions, the range of the rotational Reynolds numbers is 8.55≤ ReΩ≤ 34.20. Results indicate the ribbed design with aspect ratio 2.5 (7.5 mm wide and 3 mm high) yields temperature distributions with the least variation that is the highest heat transfer among the three types of circumferential ribs. This study ultimately aims to find an effective design methodology that improves the temperature distribution of RBCs with circumferentially ribbed turbulators in a real-time 4WD vehicle. Finally, experimental results for circumferentially ribbed turbulators with three aspect ratios were empirically correlated.
Thermally activated mobile ejector refrigeration system analysis
Authors: Salim M
Published: September 2004

A waste-heat activated vapour ejector refrigeration cycle for automotive air-conditioning applications was studied and analysed. Conservation equations of continuity, momentum, and energy were solved simultaneously, and pressures, temperatures, enthalpies, and mass flow rates at various points in the cycle were computed. The ejector system energy requirements were compared to the available energy in the exhaust gas and the engine coolant. It was found that the engine's coolant energy is superior to that of the exhaust heat energy in activating the system, for most of the engines considered. When considering the exhaust heat, only partial cooling loads up to 1.25 tons of refrigeration could be accomodated. During start-up, when the coolant temperature is not high enough, a supplemental heating system would be necessary.
Turbulent time-frequency spectral structures and the extraction of the desired turbulence component
Authors: Liao S Y , Jiang D M , Cheng Q
Published: September 2004

Turbulence is induced in a constant-volume bomb using the motion of a perforated plate. Statistical ensemble-averaged and the cycle-resolved analyses are performed for these raw velocity data. It is shown that the cycle-resolved analysis is a suitable method of characterizing non-stationary turbulent flow. Based on the cycle-resolved analysis, the velocity data are then processed using wavelet packet and moving time-window techniques to obtain turbulent time-frequency spectral structures. From the comparison of the turbulent time-frequency spectral properties, a method to induce turbulence with different characteristic parameters is developed. To extract the desired turbulence frequency content, a multiple cut-off frequencytechnique is proposed and good agreement is found between the results obtained from wavelet analysis and the multiple cut-off frequency method. The integral time scale of the turbulence component has been studied as well. It is shown that the integral time scale is the key characteristic time for the turbulence and this is a function of the turbulence frequency.
Flow maldistribution measurements in wall-flow diesel filters
Authors: Stratakis G A , Stamatelos A M
Published: September 2004

Understanding the flow maldistribution phenomena inside porous ceramic diesel particulate filters and their effects on the pressure drop and regeneration characteristics is important for the successful design and modelling of this class of exhaust aftertreatment system. In this paper the results from an experimental study of flow distribution in wall-flow diesel filters are presented. The experiments were performed on a specially designed cold flow test rig, under steady state flow conditions. The flow distribution at the exit of cordierite and SiC filters were measured with a hot film velocity sensor under low and medium mass flowrate conditions. The system configuration was varied to incorporate tests with and without the installation of an oxidation catalyst before the filter in order to investigate the effect of the catalyst honeycomb structure to the measured flow distribution. Flow distribution in filters loaded with various levels of particulate mass was also measured using the same device. The filters were loaded in a modern diesel engine run on catalyst-doped fuel up to different backpressure levels. A flow uniformity index was adopted in order to quantify the measured flow maldistribution by a single number for each case. The velocity distribution at the exit of the filters is found to be significantly affected by certain design and operating parameters of the system: diffuser-catalyst-filter. The results of this work aim to give a better assessment of the magnitude of flow maldistribution in diesel filters, which severely distort their pressure drop characteristics and affect the distribution of collected soot mass. In this way, a previously neglected aspect of the complex three-dimensional filter regeneration behaviour is better understood.
A Lagrangian trajectory filter for constituent data assimilation
Authors: Lyster Peter M. , Cohn Stephen E. , Zhang Banglin , Chang Lang‐Ping , Ménard Richard , Olson Kevin , Renka Robert
Published: September 2004

We have developed a new numerical algorithm, the Lagrangian filter, for solving the Kalman filter equations for assimilation of constituent observations directly on trajectories that propagate with the flow. This is a finite‐dimensional approximation of the solution of the state estimation problem by characteristics, and may be thought of as an extension of methods such as trajectory mapping. The Lagrangian filter provides a natural framework for the study and solution of the constituent data assimilation problem because of the conservative properties of the state and its estimation‐error variance and covariance along trajectories. Considerable insight into the behaviour of the filter is gained as a result of these properties. The Lagrangian filter also requires significantly fewer floating point operations than the Eulerian Kalman filter because of its simple error covariance propagation step. We implemented it for two‐dimensional flow on isentropes in the stratosphere and assimilated methane observations from the Upper Atmosphere Research Satellite. Results are validated against those of the Eulerian filter. Copyright © 2004 Royal Meteorological Society
North Atlantic forcing of climate and its uncertainty from a multi‐model experiment
Authors: Rodwell M. J. , Drévillon M. , Frankignoul C. , Hurrell J. W. , Pohlmann H. , Stendel M. , Sutton R. T.
Published: September 2004

To understand recent climate change in the North Atlantic region and to produce better climate forecasts with uncertainty estimates it is important to determine the atmospheric ‘response’ to Atlantic sea‐surface temperature (SST) forcing. There have been conflicting results regarding the strength, character and tropical‐versus‐extratropical origin of this response. For model‐based studies, this may indicate differing sensitivities to Atlantic SST, but the comparison is complicated by changes in experimental design. Here, a highly controlled experiment with five atmospheric models is undertaken. The influence of realistic (if reasonably strong) and optimally chosen North Atlantic (equator to 70°N) SST anomalies is isolated. Unexpected global agreement between the models is found (e.g. the North Atlantic Oscillation (NAO), Eurasian temperatures, rainfall over the Americas and Africa, and the Asian monsoon). The extratropical North Atlantic region response appears to be associated with remote Caribbean and tropical Atlantic SST anomalies, and with local forcing. Some features such as the European winter‐temperature response would be stronger than atmospheric ‘noise’ if the prescribed SST anomalies persisted for just two years. More generally, Atlantic air–sea interaction appears to be important for climate variability on the 30‐year timescale and, thus, to be important in the climate‐change context. The multi‐model mean response patterns are in reasonable agreement with observational estimates, although the model response magnitudes may be too weak. The similarity between their responses helps to reconcile models. Inter‐model differences do still exist and these are discussed and quantified. © Crown copyright, 2004.
Diagnostics of linear and incremental approximations in 4D‐Var
Authors: Tr'emolet Yannick
Published: September 2004

The validity of the tangent linear approximation and of the incremental 4D‐Var formulation is evaluated in the operational context. In ECMWF's operational system, the linear and adjoint models are run at a lower resolution than the nonlinear model. Furthermore, the physics are simpler in the tangent linear and adjoint than in the nonlinear model. Comparisons are made between the output of the linear model and the finite difference obtained by running the nonlinear model twice, with and without adding the analysis increment. The accuracy of the linear model is assessed with respect to resolution, linearized physics and the length of the assimilation window.

The most striking results are that linearization errors are larger than expected and that large errors appear very early in the assimilation window. It is also shown that higher resolution 4D‐Var will require more accurate linear physics than currently available. A modification of the computation of the trajectory around which the problem is linearized is shown to improve the accuracy of the linearization.

The results and diagnostic tools presented should provide guidance for further developments of the incremental 4D‐Var, with respect to resolution changes and improvements in linearized physics and dynamics. Copyright © 2004 Royal Meteorological Society
The effect of raindrop clustering on collision‐induced break‐up of raindrops
Authors: McFarquhar Greg M.
Published: September 2004

The impact of raindrop clustering on raindrop mean free paths, mean times between raindrop collisions, and raindrop collision rates is examined using prior observations of raindrop pair cross‐correlation functions and raindrop size distributions (RSDs). Variations in observed RSDs cause collision rates to vary by more than a factor of 2.5 for identical rain rates; effects due to raindrop clustering also increase collision rates by 2.5 times or more. High uncertainty in the factor of 2.5 and its variability exists because observations of raindrop inter arrival times, upon which observations of clustering are based, are relatively rare. Clustering increases collision rates because large raindrops in preferred or clustered regions overtake smaller drops in the same regions. The form of the RSD has a significant impact on the collision frequency because the spread in raindrop fall speeds, and hence the ability of large drops to overtake small ones, depends highly on the RSD.

Depending on the form of the RSD that develops at precipitation onset, numerical models suggest that there can be sufficient raindrop interactions to approach equilibrium distributions generated from the opposing forces of coalescence and break‐up for rain rates higher than about 50 mm h−1. However, equilibrium distributions do not occur in nature, most likely because the large spread in fragment size distributions generated for a specific pair of colliding raindrops causes substantial local variations in RSDs. Significant sampling times under conditions of heavy rain would be required to return to the form of an equilibrium distribution from statistical effects alone, if it indeed existed. Copyright © 2004 Royal Meteorological Society
Evaluation of Quality-Control Criteria for Microarray Gene Expression Analysis
Authors: Dumur Catherine I , Nasim Suhail , Best Al M , Archer Kellie J , Ladd Amy C , Mas Valeria R , Wilkinson David S , Garrett Carleton T , Ferreira-Gonzalez Andrea
Published: September 2004

Background: Development of quality-control criteria to ensure reproducibility of microarray results for potential clinical application is still in its infancy.

Methods: In the present studies we developed quality-control criteria and evaluated their effect in microarray data analysis using total RNA from cell lines, frozen tumors, and a commercially available reference RNA. Quality-control criteria such as A260/A280 ratios, percentage of rRNA, and median size of cDNA and cRNA synthesis products were evaluated for robustness in microarray analysis. Furthermore, precision studies using a reference material were performed on the Affymetrix® HG-U133A high-density oligonucleotide microarrays. The same reference RNA sample was examined in 16 different chips run on 2 different days in the four different modules of the Affymetrix fluidics workstation. Fresh and frozen fragmented cRNAs were also compared. An ANOVA model was fit to identify the main sources of variation.

Results: Good-quality samples showed >30% rRNA in the electropherograms and cDNA and cRNA synthesis products with median sizes of 2.0 and 3.0 kb, respectively. Precision studies showed that the main source of variation was the day-to-day variability, minimally affecting hybridization exogenous control genes. Altogether, the results showed that the Affymetrix Genechip® system is highly reproducible when RNA that meet the quality-control criteria are used (overall P >0.01).

Conclusions: These results confirm the need to establish defined quality-control criteria for sample quality to distinguish between analytical and biological variability.
Reverse Transcription-Multiplex PCR Assay for Simultaneous Detection of Escherichia coli O157:H7, Vibrio cholerae O1, and Salmonella Typhi
Authors: Morin Nicole J , Gong Zhilong , Li Xing-Fang
Published: September 2004

Background: Escherichia coli O157:H7, Vibrio cholerae O1, and Salmonella Typhi are pathogenic bacteria that can be found in contaminated water supplies throughout the world. No currently available assays can simultaneously detect and identify all three pathogens. Our aim was to develop a rapid and reliable technique for simultaneous detection of these pathogens.

Methods: Four unique genes were chosen as the targets of detection. Forward and reverse primers were designed to specifically amplify different sizes of these target genes: a 239-bp region of the E. coli O157 lipopolysaccharide (LPS) gene (rfbE); a 179-bp region of the H7 flagellin gene (fliC); a 419-bp region of the V. cholerae O1 LPS gene (rfbE); and a 329-bp region of Salmonella Typhi LPS gene (tyv). To ensure the detection of only viable replicating bacteria, RNA was extracted for analysis. After reverse transcription, cDNAs were simultaneously amplified in a single tube by multiplex PCR. The multiplex PCR products were analyzed by gel electrophoresis. To characterize the assay we analyzed, in a blinded fashion, seven unknown RNA samples containing various combinations of total RNA from these bacteria as well as clinical isolates.

Results: All seven unknown RNA samples were correctly identified. The assay was able to detect and identify as few as 30 cells of E. coli O157:H7 and Salmonella Typhi in clinical isolates, and the presence of other bacteria did not interfere with the analysis.

Conclusion: An assay combining reverse transcription with single-tube multiplex PCR was successfully developed and validated for simultaneous detection of viable E. coli O157:H7, V. cholerae O1, and Salmonella Typhi.
The Isolation of Specific Bio-Control Agents for the Dry Rot Fungus Serpula Lacrymans
Authors: Phillips-Laing E. M. , Staines H. J. , Palfreyman J. W.
Published: September 2004

New Trichoderma isolates were prepared from soils collected in the areas of the world where the
dry rot fungus Serpula lacrymans is indigenous. Agar-screening tests were carried out to identify
the antagonistic effects of isolates and determine if their mode of action was geared towards production
of volatiles. Overall, Trichoderma isolates from Northern California, USA, were found to
be extremely effective against S. lacrymans (Schumacher ex Fr. Gray.) and some produced a killing
effect in the agar systems. In addition, these isolates inhibited S. lacrymans growth by volatile production
even in the absence of direct contact between the Trichoderma isolate and S. lacrymans,
whereas a standard laboratory culture of Trichoderma harzianum T25 was found to be much less
effective. In two different soil and wood microcosms the USA isolates were also able to stop the
growth of S. lacrymans and produced an apparent killing effect.
Termiticidal Performance of Wood-Based Composites Treated with Silafluofen Using Supercritical Carbon Dioxide
Authors: Muin M. , Tsunoda K.
Published: September 2004

The termiticidal performance of wood-based composites [medium density fiberboard (MDF),
hardwood plywood, softwood plywood, particleboard and oriented strand board (OSB)] was evaluated
following treatment with a non-ester pyrethroid, silafluofen, using supercritical carbon dioxide
(SC-CO2) as a carrier solvent. Treatment was conducted under nine combinations of temperature
(35°C, 45°C or 55°C) and pressure [7.85 MPa (80 kgf/cm2), 9.81 MPa (100 kgf/cm2) or
11.77 MPa (120 kgf/cm2)]. Treated and untreated samples were individually exposed to the subterranean
termite Coptotermes formosanus Shiraki in the laboratory, and the percent mass loss of the
samples and termite mortality were determined to compare the termiticidal performance among
the wood-based composites and treatment conditions. Silafluofen/SC-CO2 treatment significantly
improved the termite resistance of all of the wood-based composites, although the termiticidal performance
varied with the composite type and treatment conditions. The best performance for
MDF, hardwood plywood, softwood plywood and particleboard was obtained at 35°C-7.85 MPa in
terms of the inhibition of feeding, and gave high termite mortality and energy-conservation,
whereas the best performance for OSB was at 35°C and 9.81 MPa or 11.77 MPa.
Topochemical Investigations on Delignification of Picea abies [L.] Karst. during Alkaline Sulfite (ASA) and Bisulfite Pulping by Scanning UV Microspectrophotometry
Authors: Koch G. , Rose B. , Patt R. , Kordsachia. O.
Published: September 2004

Delignification of spruce (Picea abies [L.] Karst.) during ASA (modified alkaline sulfite/anthraquinone
pulping with alkali splitting) and magnesium bisulfite pulping was studied on a cellular
level using scanning UV microspectrophotometry. This improved cellular analytical technique
enables direct imaging of the topochemistry of lignin removal within the cell wall at different
stages of cooking. The cooks were performed in a laboratory digester with forced liquor circulation.
At 30 min intervals samples were taken for chemical and UV microscopic analyses. UV microscopy
reveals that delignification during ASA pulping starts in the region of the pit canals and
proceeds evenly across the entire S2 layer. As a specific feature of bisulfite pulping, a partial delignification
of the radial compound middle lamella can be detected after 60 min of cooking. After
120 min, in both processes, the delignified cell walls show low UV absorbance values of both S2
and compound middle lamella. At this stage, approximately 90% of the initial lignin content is removed.
At the end of both pulping processes, only parts of the cell corners can be distinguished by
the new UV scanning technique.
Effect of growth site type, felling season, storage time and kiln drying on contents and distributions of phenolic extractives and low molar mass carbohydrates in secondary xylem of silver birch Betula pendula
Authors: Mononen K. , Alvila L. , Pakkanen T. T.
Published: September 2004

The effect of growth site type, felling season, storage time and kiln drying on the contents and distributions of phenolic extractives and low molar mass carbohydrates in secondary xylem of silver birchBetula pendulawas studied. The results indicated that the total amount of methanol-soluble extractives did not change markedly under the prevailing conditions of the study. However, the contents of phenolic compounds, (+)-catechin and (+)-catechin-7-O-β-D-xylopyranoside, and low molar mass sugars, D(+)-xylose, D(−)-fructose, D(+)-glucose, sucrose, maltose and raffinose, changed with season, storage time, radial location in the stem or growth site type. The glycosidic bond in (+)-catechin-7-O-β-D-xylopyranoside, sucrose, maltose and raffinose was hydrolysed with kiln drying, resulting in elevated contents of the monosaccharides, D(+)-xylose, D(−)-fructose, D(+)-glucose, in kiln dried boards. Surprisingly, the content of (+)-catechin did not increase simultaneously with the breakdown of (+)-catechin-7-O-β-D-xylopyranoside, indicating that (+)-catechin may polymerise or have another bonding pattern with other wood components due to elevated temperatures during kiln drying. In addition, the relative amount of phenolic compounds, (+)-catechin monomer and its glycoside, (+)-catechin-7-O-β-D-xylopyranoside, in the methanol extracts decreased with partial vacuum drying.
Resonance Raman spectroscopy of highly fluorescing lignin containing chemical pulps: Suppression of fluorescence with an optical Kerr gate
Authors: Saariaho A.-M. , Jääskelinen A.-S. , Matousek P. , Towrie M. , Parker A. W. , Vuorinen T.
Published: September 2004

Raman spectroscopy using 400 nm excitation was successfully applied to chemical pulp samples and the fluorescence background that usually limits the application of this method to such samples was effectively suppressed. This enabled the detection of much weaker Raman bands from the pulps. The rejection ratio of the fluorescence background to Raman scattering was estimated to be about 250. The resonance Raman spectra of peroxide bleached chemical pulps had chromophoric lignin bands at 1605 and 1655 cm−1, whereas the chlorine dioxide bleached pulps had only the aromatic band at 1605 cm−1. The square root of the aromatic chromophore band relative to cellulose band correlated linearly with the brightness which is in accordance with the Kubelka-Munk theory. This correlation indicated that the resonance enhanced Raman bands were mainly due to chromophoric lignin structures. Chlorine dioxide and peroxide bleached pulps gave different correlations to brightness, which was an indication of different kinds of chromophores in these pulps. The intensity of the aromatic band relative to the cellulose band was about 20 times higher with the ultraviolet (257 nm) than with the visible (400 nm) excitation. This clearly illustrated the importance of working with different excitation wavelengths. On one hand the UV excitation is more sensitive towards aromatic residual lignin in pulp, and on the other hand the visible excitation enables the selective detection of chromophoric lignin structures.
Variation in microfibril angle in Eucalyptus clones
Authors: Lima J. T. , Breese M. C. , Cahalan C. M.
Published: September 2004

The microfibril angle of the S2 layer in wood fibres is an
ultra-microscopical feature that influences important
properties affecting the utilisation of timber. However, this
characteristic is as yet little studied, and this is especially
true of the genus Eucalyptus. The microfibril angle of the
S2 layer of the secondary wall was measured in fibres
taken from eight-year-old trees of 11 Eucalyptus clones
growing in four sites in Brazil. The overall mean microfibril
angle measured was 8.8°. While the angle seemed to
decrease slightly from pith to bark in a non-linear fashion,
this decrease was not statistically significant. The microfibril
angle showed statistically significant differences
between sites and between clones, although the broad
sense heritability of the microfibril angel was low
(h2=0.293). Various theories attempt to explain the
microfibril orientation, but we conclude that environmental
stresses play an important role in defining the angle
in Eucalyptus wood.
Durability of untreated Norway spruce (Picea abies) exposed outdoors above ground for nine years
Authors: Bergström M. , Rydell Å. , Elowson T.
Published: September 2004

Moisture dynamics and durability during weather exposure
as affected by origin and production method were
studied for nine years on 113 untreated spruce samples.
The moisture content was measured on 67 occasions.
The weight loss was determined for each sample at the
end of the sampling period. The most important factors,
affecting both moisture content and weight loss, were
origin and drying technique. The samples originating
from central Sweden had the best durability, followed by
the southern stand, while the northern stand had the lowest
durability in terms of weight loss. Air-drying had a
negative impact on the performance of samples from all
three stands, but to different degrees. Samples from the
northern stand were most sensitive to air-drying, in terms
of both weight loss and moisture content, followed by
the southern stand, while the central stand was least
sensitive. Why the samples from the northern stand were
more sensitive to air-drying and showed the largest
weight losses is unknown; it can only be suggested that
the origin of the wood can be of importance for the
durability.
Microbial colonizers of freshly sawn yellow-poplar (Liriodendron tulipifera L.) lumber in two seasons: Part 2. Bacteria
Authors: Mikluscak M. R. , Dawson-Andoh B. E.
Published: September 2004

This paper reports on the identity and frequency of isolation of bacteria colonizing freshly-sawn (green) yellow-poplar lumber dead-stacked for 60 days in spring and summer of 2000. Total abundance of bacteria comprised 43% of the total population of isolated microorganisms and 14 different species of bacteria were identified.Bacillussp was the predominant species and accounted for 42% of the total bacteria positively identified. Abundance of bacteria on each sampling date increased with increasing average ambient temperature in the period leading up to sampling.
Ceramidase Regulates Synaptic Vesicle Exocytosis and Trafficking
Authors: Rohrbough Jeffrey , Rushton Emma , Palanker Laura , Woodruff Elvin , Matthies Heinrich J. G. , Acharya Usha , Acharya Jairaj K. , Broadie Kendal
Published: September 2004

A screen forDrosophilasynaptic dysfunction mutants identifiedslug-a-bed(slab). Theslabgene encodes ceramidase, a central enzyme in sphingolipid metabolism and regulation. Sphingolipids are major constituents of lipid rafts, membrane domains with roles in vesicle trafficking, and signaling pathways. Nullslabmutants arrest as fully developed embryos with severely reduced movement. The SLAB protein is widely expressed in different tissues but enriched in neurons at all stages of development. Targeted neuronal expression ofslabrescues mutant lethality, demonstrating the essential neuronal function of the protein. C5-ceramide applied to living preparations is rapidly accumulated at neuromuscular junction (NMJ) synapses dependent on the SLAB expression level, indicating that synaptic sphingolipid trafficking and distribution is regulated by SLAB function. Evoked synaptic currents atslabmutant NMJs are reduced by 50-70%, whereas postsynaptic glutamate-gated currents are normal, demonstrating a specific presynaptic impairment. Hypertonic saline-evoked synaptic vesicle fusion is similarly impaired by 50-70%, demonstrating a loss of readily releasable vesicles. In addition, FM1-43 dye uptake is reduced inslabmutant presynaptic terminals, indicating a smaller cycling vesicle pool. Ultrastructural analyses of mutants reveal a normal vesicle distribution clustered and docked at active zones, but fewer vesicles in reserve regions, and a twofold to threefold increased incidence of vesicles linked together and tethered at the plasma membrane. These results indicate that SLAB ceramidase function controls presynaptic terminal sphingolipid composition to regulate vesicle fusion and trafficking, and thus the strength and reliability of synaptic transmission.
Differential Roles of NR2A and NR2B-Containing NMDA Receptors in Cortical Long-Term Potentiation and Long-Term Depression
Authors: Massey Peter V. , Johnson Benjamin E. , Moult Peter R. , Auberson Yves P. , Brown Malcolm W. , Molnar Elek , Collingridge Graham L. , Bashir Zafar I.
Published: September 2004

It is widely believed that long-term depression (LTD) and its counterpart, long-term potentiation (LTP), involve mechanisms that are crucial for learning and memory. However, LTD is difficult to induce in adult cortex for reasons that are not known. Here we show that LTD can be readily induced in adult cortex by the activation of NMDA receptors (NMDARs), after inhibition of glutamate uptake. Interestingly there is no need to activate synaptic NMDARs to induce this LTD, suggesting that LTD is triggered primarily by extrasynaptic NMDA receptors. We also find thatde novoLTD requires the activation of NR2B-containing NMDAR, whereas LTP requires activation of NR2A-containing NMDARs. Surprisingly another form of LTD, depotentiation, requires activation of NR2A-containing NMDARs. Therefore, NMDARs with different synaptic locations and subunit compositions are involved in various forms of synaptic plasticity in adult cortex.