bluuebunny/crossref_metadata_2025 huggingface dataset:
Cerebral energetic effects of creatine supplementation in humans
Authors: Pan J. W. , Takahashi K.
Published: December 2006

There has been considerable interest in the use of creatine (Cr) supplementation to treat neurological disorders. However, in contrast to muscle physiology, there are relatively few studies of creatine supplementation in the brain. In this report, we use high-field MR 31P and 1H spectroscopic imaging of human brain with a 7-day protocol of oral Cr supplementation to examine its effects on cerebral energetics (phosphocreatine, PCr; ATP) and mitochondrial metabolism ( N-acetyl aspartate, NAA; and Cr). We find an increased ratio of PCr/ATP ( day 0, 0.80 ± 0.10; day 7, 0.85 ± 09), with this change largely due to decreased ATP, from 2.7 ± 0.3 mM to 2.5 ± 0.3 mM. The ratio of NAA/Cr also decreased ( day 0, 1.32 ± 0.17; day 7 1.18 ± 0.13), primarily from increased Cr (9.6 ± 1.9 to 10.1 ± 2.0 mM). The Cr-induced changes significantly correlated with the basal state, with the fractional increase in PCr/ATP negatively correlating with the basal PCr/ATP value ( R = −0.74, P < 0.001). As NAA is a measure of mitochondrial function, there was also a significant negative correlation between basal NAA concentrations with the fractional change in PCr and ATP. Thus healthy human brain energetics is malleable and shifts with 7 days of Cr supplementation, with the regions of initially low PCr showing the largest increments in PCr. Overall, Cr supplementation appears to improve high-energy phosphate turnover in healthy brain and can result in either a decrease or an increase in high-energy phosphate concentrations.
Identification of a novel signal in the cytoplasmic tail of the Na+:HCO3−cotransporter NBC1 that mediates basolateral targeting
Authors: Li Hong C. , Li Emily Y. , Neumeier Lisa , Conforti Laura , Soleimani Manoocher
Published: December 2006

The Na+:HCO3−cotransporter NBC1 (SLC4A4, variant A, kidney specific) is located exclusively on the basolateral membrane of epithelial cells, implying that this molecule has acquired specific signals for targeting to the basolateral membrane. A motif with the sequence QQPFLS (positions 1010–1015) in the cytoplasmic tail of NBC1 was recently demonstrated to mediate targeting of NBC1 to the basolateral membrane. Here, we demonstrate that mutating the amino acid F (phenylalanine) or L (leucine) at positions 1013 or 1014 to alanine, respectively, resulted in the retargeting of NBC1 to the apical membrane. Furthermore, mutation of the FL motif to FF showed similar properties as the wild-type; however, mutation of the FL motif to LL showed significant intracellular retention of NBC1. Mutating the amino acids Q-Q-P and S (positions 1010-1011-1012 and 1015) to A-A-A and A, respectively, did not affect the membrane targeting of NBC1. Functional studies in oocytes with microelectrode demonstrated that the apically targeted mutants, as well as basolaterally targeted mutants, are all functional. We propose that the FL motif in the COOH-terminal tail of NBC1 is essential for the targeting of NBC1 to the basolateral membrane but is distinct from the membrane-targeting di-leucine motif identified in other membrane proteins.
Acute Clozapine Suppresses Synchronized Pyramidal Synaptic Network Activity by Increasing Inhibition in the Ferret Prefrontal Cortex
Authors: Gao Wen-Jun
Published: December 2006

Recent studies have indicated that impaired neural circuitry in the prefrontal cortex is a prominent feature of the neuropathology of schizophrenia. Clozapine is one of the most effective antipsychotic drugs used for this debilitating disease. Despite its effectiveness, the mechanism by which clozapine acts on prefrontal cortical circuitry remains poorly understood. In this study, in vitro multiple whole cell recordings were performed in slices of the ferret prefrontal cortex. Clozapine, which effectively inhibited the spontaneous synchronized network activities in the prefrontal neurons, achieved the suppressive effect by decreasing the recurrent excitation among pyramidal neurons and by enhancing the inhibitory inputs onto pyramidal cells through a likely network mechanism. Indeed, under the condition of disinhibition, the depressing effects were reversed and clozapine enhanced the recurrent excitation. These results suggest that the therapeutic actions of clozapine in alleviating the positive symptoms of schizophrenia are achieved, at least partially, through the readjustment of synaptic balance between the excitation and inhibition in the prefrontal cortical circuitry.
Bayesian Filtering of Myoelectric Signals
Authors: Sanger Terence D.
Published: December 2006

Surface electromyography is used in research, to estimate the activity of muscle, in prosthetic design, to provide a control signal, and in biofeedback, to provide subjects with a visual or auditory indication of muscle contraction. Unfortunately, successful applications are limited by the variability in the signal and the consequent poor quality of estimates. I propose to use a nonlinear recursive filter based on Bayesian estimation. The desired filtered signal is modeled as a combined diffusion and jump process and the measured electromyographic (EMG) signal is modeled as a random process with a density in the exponential family and rate given by the desired signal. The rate is estimated on-line by calculating the full conditional density given all past measurements from a single electrode. The Bayesian estimate gives the filtered signal that best describes the observed EMG signal. This estimate yields results with very low short-time variability but also with the capability of very rapid response to change. The estimate approximates isometric joint torque with lower error and higher signal-to-noise ratio than current linear methods. Use of the nonlinear filter significantly reduces noise compared with current algorithms, and it may therefore permit more effective use of the EMG signal for prosthetic control, biofeedback, and neurophysiology research.
The Impact of Earmarked Lottery Revenue on K–12 Educational Expenditures
Authors: Evans William N. , Zhang Ping
Published: December 2006

Of thirty-eight states with lotteries, sixteen earmark lottery profits for primary and secondary education. In this article, we use a panel data set of states with lotteries to examine the impact of earmarking lottery revenues on state educational spending. We can reject the hypothesis that spending increases dollar for dollar with earmarked profits, but there is a high likelihood that earmarking increases school spending more than non-earmarking. We find that 50–70 cents out of an earmarked dollar finds its way to local school districts. In contrast, each dollar of lottery profits increases state revenues to schools by about 30 cents in states that deposit profits into the general fund. Of the lottery dollars that reach local school districts, we find that at least 80 percent of it is spent on schools.
Understanding Normal Modes of Molecules and Clusters
Authors: Hug W.
Published: December 2006

Traditional methods for characterizing molecular vibrations were developed for small molecules and are not well suited for understanding nuclear motions of large molecules and of clusters. We present a procedure based on representing normal modes, including translations and rotations, as vectors in 3N dimensional space, where N is the number of nuclei. Double-contracting dyads formed from them allows for a quantitative definition of the overlap and the similarity of nuclear motions of whole molecules, of clusters of molecules, and of arbitrary fragments.
Dynamical Origin of Low-Frequency Variability in a Highly Nonlinear Midlatitude Coupled Model
Authors: Kravtsov S. , Berloff P. , Dewar W. K. , Ghil M. , McWilliams J. C.
Published: December 2006

A novel mechanism of decadal midlatitude coupled variability, which crucially depends on the nonlinear dynamics of both the atmosphere and the ocean, is presented. The coupled model studied involves quasigeostrophic atmospheric and oceanic components, which communicate with each other via a constant-depth oceanic mixed layer. A series of coupled and uncoupled experiments show that the decadal coupled mode is active across parameter ranges that allow the bimodality of the atmospheric zonal flow to coexist with oceanic turbulence. The latter is most intense in the regions of inertial recirculation (IR). Bimodality is associated with the existence of two distinct anomalously persistent zonal-flow modes, which are characterized by different latitudes of the atmospheric jet stream. The IR reorganizations caused by transitions of the atmosphere from its high- to low-latitude state and vice versa create sea surface temperature anomalies that tend to induce transition to the opposite atmospheric state. The decadal–interdecadal time scale of the resulting oscillation is set by the IR adjustment; the latter depends most sensitively on the oceanic bottom drag. The period T of the nonlinear oscillation is 7–25 yr for the range of parameters explored, with the most realistic parameter values yielding T ≈ 20 yr.

Aside from this nonlinear oscillation, an interannual Rossby wave mode is present in all coupled experiments. This coupled mode depends neither on atmospheric bimodality, nor on ocean eddy dynamics; it is analogous to the mode found previously in a channel configuration. Its time scale in the model with a closed ocean basin is set by cross-basin wave propagation and equals 3–5 yr for a basin width comparable with the North Atlantic.
A Distribution Law for Free-Tropospheric Relative Humidity
Authors: Sherwood Steven C. , Kursinski E. Robert , Read William G.
Published: December 2006

The probability distribution of local relative humidity ℛ in the free troposphere is explored by comparing a simple theoretical calculation with observations from the global positioning system (GPS) and the Microwave Limb Sounder (MLS). The calculation is based on a parcel of air that conserves its composition during diabatic subsidence, until it is resaturated by randomly entering a convective system. This simple “advection–condensation” model of relative humidity predicts a probability density for ℛ proportional to ℛr−1, where r is the ratio of time scales associated with subsidence drying and random moistening. The observations obey this distribution remarkably well from 600 to 200 hPa in the Tropics and midlatitudes; possible reasons for this are discussed. The lowest values of ℛ are predicted, and observed, to be the most probable. The observed vertical variation of ℛ is well explained by that of the subsidence time scale, which is set by large-scale dynamics and radiation. These results imply that cloud microphysics exerts little control on water vapor’s greenhouse effect, but that relatively subtle dynamical changes have the potential to alter the strength of its feedback on climate change.
The General Circulation and Robust Relative Humidity
Authors: Sherwood S. C. , Meyer C. L.
Published: December 2006

The sensitivity of free-tropospheric relative humidity to cloud microphysics and dynamics is explored using a simple 2D humidity model and various configurations of the National Center for Atmospheric Research (NCAR) Community Atmosphere Model version 3 (CAM3) atmospheric general circulation model (AGCM). In one configuration the imposed surface temperatures and radiative perturbations effectively eliminated the Hadley and Walker circulations and the main westerly jet, creating instead a homogeneous “boiling kettle” world in low and midlatitudes. A similarly homogeneous state was created in the 2D model by rapid horizontal mixing.

Relative humidity ℛ simulated by the AGCM was insensitive to surface warming. Doubling a parameter governing cloud water reevaporation increased tropical mean ℛ near the midtroposphere by about 4% with a realistic circulation, but by more than 10% in the horizontally homogeneous states. This was consistent in both models. AGCM microphysical sensitivity decreased in the upper troposphere, and vanished outside the Tropics. Convective organization by the general circulation evidently makes relative humidity much more robust to microphysical details by concentrating the rainfall in moist environments. Models that fail to capture this will overestimate the microphysical sensitivity of humidity.

Based on these results, the uncertainty in the strength of the water vapor feedback associated with cloud microphysical processes seems unlikely to exceed a few percent. This does not include uncertainties associated with large-scale dynamics or cloud radiative effects, which cannot be quantified, although radical CAM3 circulation changes reported here had surprisingly little impact on simulated relative humidity.
PDO–ENSO Effects in the Climate of Mexico
Authors: Pavia Edgar G. , Graef Federico , Reyes Jorge
Published: December 2006

The role of the Pacific decadal oscillation (PDO) in El Niño–Southern Oscillation (ENSO)-related Mexican climate anomalies during winter and summer is investigated. The precipitation and mean temperature data of approximately 1000 stations throughout Mexico are considered. After sorting ENSO events by warm phase (El Niño) and cold phase (La Niña) and prevailing PDO phase: warm or high (HiPDO) and cold or low (LoPDO), the authors found the following: 1) For precipitation, El Niño favors wet conditions during summers of LoPDO and during winters of HiPDO. 2) For mean temperature, cooler conditions are favored during La Niña summers and during El Niño winters, regardless of the PDO phase; however, warmer conditions are favored by the HiPDO during El Niño summers.
Prediction of Clouds and Rain Using a z-Coordinate Nonhydrostatic Model
Authors: Steppeler J. , Bitzer H. W. , Janjic Z. , Schättler U. , Prohl P. , Gjertsen U. , Torrisi L. , Parfinievicz J. , Avgoustoglou E. , Damrath U.
Published: December 2006

The most common option for numerical models of the atmosphere is to use model layers following the surface of the earth, using a terrain-following vertical coordinate. The present paper investigates the forecast of clouds and precipitation using the z-coordinate nonhydrostatic version of the Lokalmodell (LM-z). This model uses model layers that are parallel to the surface of the sphere and consequently intersect the orography. Physical processes are computed on a special grid, allowing adequate grid spacing even over high mountains. In other respects the model is identical to the nonhydrostatic terrain-following version of the LM, which in a number of European countries is used for operational mesoscale forecasting. The terrain-following version of the LM (LM-tf) is used for comparison with the forecasts of the LM-z. Terrain-following coordinates are accurate when the orography is shallow and smooth, while z-coordinate models need not satisfy this condition. Because the condition of smooth orography is rarely satisfied in reality, z-coordinate models should lead to a better representation of the atmospheric flow near mountains and consequently to a better representation of fog, low stratus, and precipitation. A number of real-data cases, computed with a grid spacing of 7 and 14 km, are investigated. A total of 39 real-data cases have been used to evaluate forecast scores. A rather systematic improvement of precipitation forecasts resulted in a substantial increase of threat scores. Furthermore, RMS verification against radiosondes showed an improvement of the 24-h forecast, both for wind and temperature. To investigate the possibility of flow separation at mountain tops, the flow in the lee of southern Italy was investigated.
Climate Modeling with Spectral Elements
Authors: Baer Ferdinand , Wang Houjun , Tribbia Joseph J. , Fournier Aimé
Published: December 2006

As an effort toward improving climate model–component performance and accuracy, an atmospheric-component climate model has been developed, entitled the Spectral Element Atmospheric Climate Model and denoted as CAM_SEM. CAM_SEM includes a unique dynamical core coupled at this time to the physics component of the Community Atmosphere Model (CAM) as well as the Community Land Model. This model allows the inclusion of local mesh refinement to seamlessly study imbedded higher-resolution regional climate concurrently with the global climate. Additionally, the numerical structure of the model based on spectral elements allows for application of state-of-the-art computing hardware most effectively and economically to produce the best prediction/simulation results with minimal expenditure of computing resources. The model has been tested under various conditions beginning with the shallow water equations and ending with an Atmospheric Model Intercomparison Project (AMIP)-style run that uses initial conditions and physics comparable to the CAM2 (version 2 of the NCAR CAM climate model) experiments. For uniform resolution, the output of the model compares favorably with the published output from the CAM2 experiments. Further integrations with local mesh refinement included indicate that while greater detail in the prediction of mesh-refined regions—that is, regional climate—is observed, the remaining coarse-grid results are similar to results obtained from a uniform-grid integration of the model with identical conditions. It should be noted that in addition to spectral elements, other efficient schemes have lately been considered, in particular the finite-volume scheme. This scheme has not yet been incorporated into CAM_SEM. The two schemes—finite volume and spectral element—are quasi-independent and generally compatible, dealing with different aspects of the integration process. Their impact can be assessed separately and the omission of the finite-volume process herein will not detract from the evaluation of the results using the spectral-element method alone.
Objective Estimation of Tropical Cyclone Wind Structure from Infrared Satellite Data
Authors: Mueller Kimberly J. , DeMaria Mark , Knaff John , Kossin James P. , Vonder Haar Thomas H.
Published: December 2006

Geostationary infrared (IR) satellite data are used to provide estimates of the symmetric and total low-level wind fields in tropical cyclones, constructed from estimations of an azimuthally averaged radius of maximum wind (RMAX), a symmetric tangential wind speed at a radius of 182 km (V182), a storm motion vector, and the maximum intensity (VMAX). The algorithm is derived using geostationary IR data from 405 cases from 87 tropical systems in the Atlantic and east Pacific Ocean basins during the 1995–2003 hurricane seasons that had corresponding aircraft data available. The algorithm is tested on 50 cases from seven tropical storms and hurricanes during the 2004 season. Aircraft-reconnaissance-measured RMAX and V182 are used as dependent variables in a multiple linear regression technique, and VMAX and the storm motion vector are estimated using conventional methods. Estimates of RMAX and V182 exhibit mean absolute errors (MAEs) of 27.3 km and 6.5 kt, respectively, for the dependent samples. A modified combined Rankine vortex model is used to estimate the one-dimensional symmetric tangential wind field from VMAX, RMAX, and V182. Next, the storm motion vector is added to the symmetric wind to produce estimates of the total wind field. The MAE of the IR total wind retrievals is 10.4 kt, and the variance explained is 53%, when compared with the two-dimensional wind fields from the aircraft data for the independent cases.
MM5 Ensemble Mean Forecasts in the Taiwan Area for the 2003 Mei-Yu Season
Authors: Chien Fang-Ching , Liu Yi-Chin , Jou Ben Jong-Dao
Published: December 2006

This paper presents an evaluation study of a real-time fifth-generation Pennsylvania State University–NCAR Mesoscale Model (MM5) mesoscale ensemble prediction system in the Taiwan area during the 2003 mei-yu season. The ensemble system consists of 16 members that used the same nested domains of 45- and 15-km resolutions, but different model settings of the initial conditions (ICs), the cumulus parameterization scheme (CPS), and the microphysics scheme (MS). Verification of geopotential height, temperature, relative humidity, and winds in the 15-km grid shows that the members using the Kain–Fritsch CPS performed better than those using the Grell CPS, and those using the Central Weather Bureau (CWB) Nonhydrostatic Forecast System (NFS) ICs fared better than those using the CWB Global Forecast System (GFS) ICs. The members applying the mixed-phase MS generally exhibited the smallest errors among the four MSs. Precipitation verification shows that the members using the Grell CPS, in general, had higher equitable threat scores (ETSs) than those using the Kain–Fritsch CPS, that the members with the GFS ICs performed better than with the NFS ICs, and that the mixed-phase and Goddard MSs gave relatively high ETSs in the rainfall simulation. The bias scores show that, overall, all 16 members underforecasted rainfall. Comparisons of the ensemble means show that, on average, an ensemble mean, no matter how many members it contains, can produce better forecasts than an individual member. Among the three possible elements (IC, CPS, and MS) that can be varied to compose an ensemble, the ensemble that contains members with all three elements varying performed the best, while that with two elements varying was second best, and that with only one varying was the worst. Furthermore, the first choice for composing an ensemble is to use perturbed ICs, followed by the perturbed CPS, and then the perturbed MS.
Discrimination and Desegregation: Equal Opportunity Progress in U.S. Private Sector Workplaces since the Civil Rights Act
Authors: Tomaskovic-Devey Donald , Stainback Kevin
Published: December 2006

Numerous commentators have concluded that the Civil Rights Act was effective in promoting increased access to quality jobs for racial minorities. Many have worried as well that the pace of change has been too slow or stalled, particularly after 1980. Few have directly discussed under what conditions we might expect equal employment opportunity (EEO) to flourish. Explanations of status inequalities in the workplace have primarily relied on theories of social conflict and discrimination. Organizational perspectives on stratification, while not completely absent from previous research, remain a road less traveled. In this paper we present trends in race-sex inequality in U.S. workplaces since the Civil Rights Act of 1964 and describe the organizational practices and discrimination processes that are likely to maintain status inequalities in the workplace and those which might be catalysts of change.
Racial Composition of Workgroups and Job Satisfaction among Whites
Authors: Maume David J. , Sebastian Rachel
Published: December 2006

Despite decades of research on job satisfaction, few analysts have examined the relative explanatory power of the demographic composition of the workgroup against traditional predictors that focus on the characteristics of workers' jobs. This article drew from the organizational demography and status composition perspectives to examine the effects of workgroup racial composition on white job satisfaction. The sample consisted of non-Hispanic whites who responded to the 2002 National Study of the Workforce. The findings showed that an increase in the number of minority coworkers negatively affected job satisfaction among whites, until the characteristics of jobs were controlled. The results support the status composition perspective in suggesting that whites are not overtly biased against minority coworkers but rather become dissatisfied with the less favored jobs they share with minorities.
What Happens to Potential Discouraged? Masculinity Norms and the Contrasting Institutional and Labor Market Experiences of Less Affluent Black and White Men
Authors: Royster Deirdre A.
Published: December 2006

Though less affluent black and white boys and men adhere to similar gendered norms and aspirations and begin with similar labor market potential, they are often sorted into very different and unequal educational and labor market trajectories. Using national-level descriptive data and key qualitative studies of institutional processes, this article contrasts less affluent black and white men’s educational, labor market, and criminal justice system experiences and elucidates the processes of differentiation that reproduce those unequal patterns. In each institutional arena, less affluent black males pay a disproportionate price for enacting masculinity norms in comparison to white males. White boys and men are also presented with more desirable labor market options (and second-chance opportunities when they need help) that are denied their black male counterparts. This article suggests that only a complex strategy, which requires less affluent black men to resist more constructively while citizen groups hold institutions more publicly accountable, can enhance the labor market trajectories of black men.
Fiber/Fiber Crosses: Finite Element Modeling and Comparison with Experiment
Authors: Torgnysdotter Annsofie , Kulachenko Artem , Gradin Per , Wågberg Lars
Published: December 2006

Fiber/fiber joints were analyzed using finite element analysis in order to characterize the influence of fiber and contact region properties on the stress— strain behavior of a single fiber/fiber cross. The output of the models was validated by comparison with experimental load—deformation curves. The contact zone of the fiber/fiber joint was studied with respect to the appearance of the contact zone, the contact area, and the contact pattern; the work of adhesion of the contact areas was also considered. It was shown that the two-dimensional appearance of the contact zone had little influence on the stress—strain behavior of the fiber/fiber cross under tensile loading. The maximum stress and hence the fiber/fiber joint strength was, however, affected by the degree of contact. It was concluded that knowledge of the material behavior of the contact zone (such as local plastic behavior), and of chemical effects (such as work of adhesion) are needed to predict the fiber/fiber joint strength.
Outpatient Transfusion Practice and Factors Leading to Inpatient Transfusion in a Pediatric Hematology/Oncology Program
Authors: Richardson Matthew , Martel Lisa , Martensson Lisa
Published: December 2006

Oral mucositis continues to be a common and debilitating side effect of the conditioning regimens that use high-dose chemotherapy with or without radiation for pediatric bone marrow transplantation. Limited interventions have demonstrated success in preventing or treating it. Administration of glutamine, which is a nitrogen-rich amino acid found in the body, has emerged as a possible method of preventing oral mucositis in patients undergoing bone marrow transplantation. Numerous studies have looked at the effects of oral glutamine supplementation during bone marrow transplant. The purpose of this article is to describe glutamine and how it functions, review the literature regarding the use of oral glutamine in the prevention of oral mucositis in bone marrow transplantion, discuss the administration concerns related to the pediatric setting, and stress the importance of the nurse's role at the bedside. Nurses working in pediatric bone marrow transplant play a key role in the assessment of oral mucositis, administration of oral glutamine, and education of the patient and family.
Needle Phobia and Stress-Reducing Medical Devices in Pediatric and Adult Chemotherapy Patients
Authors: Kettwich Sharon C. , Sibbitt Wilmer L. , Brandt John R. , Johnson Courtney R. , Wong Craig S. , Bankhurst Arthur D.
Published: December 2006

Needle phobia—fear of medical devices—is a significant problem in pediatric and adult chemotherapy patients. Stress-reducing medical devices is a new, effective cognitive therapy for needle phobia. Twenty-five pediatric and 25 adult chemotherapy patients were randomly exposed to conventional or stress-reducing decorated butterfly needles and syringes. Emotional stress responses were determined with the Visual Aversion Scale, Visual Analogue Fear Scale, Visual Analogue Anxiety Scale, and Visual Overall Stress Score for each needle and syringe design. Sixty-eight percent of the pediatric and 52% of the adult patients were overtly needle phobic, but children demonstrated significantly more aversion and stress (P < .001). Stress-reducing medical devices effectively and significantly reduced aversion, anxiety, fear, and overall stress, and were 76% effective in preventing overt needle phobia in children and 92% effective in adults (P < .001). One hundred percent of children and adults felt that stress-reducing medical devices should be available in chemotherapy clinics. Needle phobia and stress in pediatric and adult chemotherapy patients are significantly reduced by the use of stress-reducing medical devices.
The Role of Oral Glutamine in Pediatric Bone Marrow Transplant
Authors: Storey Beth
Published: December 2006

Oral mucositis continues to be a common and debilitating side effect of the conditioning regimens that use high-dose chemotherapy with or without radiation for pediatric bone marrow transplantation. Limited interventions have demonstrated success in preventing or treating it. Administration of glutamine, which is a nitrogen-rich amino acid found in the body, has emerged as a possible method of preventing oral mucositis in patients undergoing bone marrow transplantation. Numerous studies have looked at the effects of oral glutamine supplementation during bone marrow transplant. The purpose of this article is to describe glutamine and how it functions, review the literature regarding the use of oral glutamine in the prevention of oral mucositis in bone marrow transplantion, discuss the administration concerns related to the pediatric setting, and stress the importance of the nurse's role at the bedside. Nurses working in pediatric bone marrow transplant play a key role in the assessment of oral mucositis, administration of oral glutamine, and education of the patient and family.
Damage Identification of Woven Graphite/Epoxy Composite Beams using the Electrical Resistance Change Method
Authors: Hirano Yoshiyasu , Todoroki Akira
Published: December 2006

This study examines the damage identification for woven graphite/epoxy composite beams by means of an electrical resistance change method. The method has been proposed by the authors and successfully applied to cross-ply and quasi-isotropic laminates; the method has yet to be applied to woven laminates. In many practical structures, woven plies are adopted to prevent peeling of the surface layer. Therefore, a woven graphite/epoxy composite is selected as the target material of the electrical resistance change method to identify the damage. Beam type specimens consisting of woven laminates are the focus of this article. For the purpose of identification, the response surface is adopted as a solving method for the inverse problem. As a result, the method shows an excellent performance for estimating delamination crack locations and sizes.
How Should Land Be Taxed? Analyzing the Jamaican Land Value Tax
Authors: Sjoquist David L.
Published: December 2006

In 2002, Jamaica conducted a property tax revaluation, the first revaluation in nine years. In response, Jamaica reduced the property tax rates of its progressive-rate structure and added a set of property tax caps. In this article, the author reports on an analysis of the tax rate structure for its land value property tax, focusing especially on options for reforming the rate structure.
Taxing Consumption in Jamaica
Authors: Edmiston Kelly D. , Bird Richard M.
Published: December 2006

In Jamaica, as in most countries, consumption taxes in the form of a value-added tax called the general consumption tax (GCT) and several excise taxes collectively known as the special consumption tax (SCT) are critically important revenue sources, accounting for 37.4 percent of total revenues in fiscal year 2003-2004 (27.7 percent for GCT alone) and an estimated 11.2 percent of GDP (8.3 percent for GCT alone). This article describes in some detail the present structure and administration of the GCT and SCT and then evaluates the performance of these taxes from several angles—their revenue effects, their distributional effects and their relation to the shadow economy, their administrative aspects, and their relation to various international considerations. It concludes by setting out a number of recommendations for reform.
The Evolution of Jamaica’s Tax Burden
Authors: Alleyne Dillon
Published: December 2006

This study reviews four tax incidence studies, done in Jamaica since 1983, to determine the evolution of Jamaica’s tax burden. It identifies several limitations in the methodologies used that make it difficult to interpret the results without due care. For example, income bases were different, adjustment for evasion was not always satisfactory due to data limitations, and several nontax institutional features of the economy did not inform the incidence assumptions. The general conclusions are twofold: the overall tax burden has declined since 1983, and the degree of progressivity in the distribution of tax burdens increased over time. Several factors account for the change in progressivity. First, increases in the standard deduction have removed many low-income households from the direct tax net. Second, the removal of several allowances has increased the burden on high-income earners. Third, perhaps surprisingly, the indirect tax burden has tended to be proportional or even slightly progressive.
NK4, an antagonist of hepatocyte growth factor (HGF), inhibits growth of multiple myeloma cells: molecular targeting of angiogenic growth factor
Authors: Du Wenlin , Hattori Yutaka , Yamada Taketo , Matsumoto Kunio , Nakamura Toshikazu , Sagawa Morihiko , Otsuki Takemi , Niikura Takako , Nukiwa Toshihiro , Ikeda Yasuo
Published: December 2006

Hepatocyte growth factor (HGF) promotes cell growth and motility and also increases neovascularization. Multiple myeloma (MM) cells produce HGF, and the plasma concentration of HGF is significantly elevated in patients with clinically active MM, suggesting that HGF might play a role in the pathogenesis of MM. NK4, an antagonist of HGF, is structurally homologous to angiostatin, and our previous report showed that NK4 inhibited the proliferation of vascular endothelial cells induced by HGF stimulation. The purposes of this study were to elucidate the contribution of HGF to the growth of MM cells as well as to investigate the possibility of the therapeutic use of NK4. In vitro study showed that NK4 protein stabilized the growth of MM cell lines and regulated the activation of c-MET, ERK1/2, STAT3, and AKT-1. Recombinant adenovirus containing NK4 cDNA (AdCMV.NK4) was injected intramuscularly into lcr/scid mice bearing tumors derived from HGF-producing MM cells. AdCMV.NK4 significantly inhibited the growth of these tumors in vivo. Histologic examination revealed that AdCMV.NK4 induced apoptosis of MM cells, accompanied by a reduction in neovascularization in the tumors. Thus, NK4 inhibited the growth of MM cells via antiangiogenic as well as direct antitumor mechanisms. The molecular targeting of HGF by NK4 could be applied as a novel therapeutic approach to MM.
A minimally invasive multiple marker approach allows highly efficient detection of meningioma tumors
Authors: Keller Andreas , Ludwig Nicole , Comtesse Nicole , Hildebrandt Andreas , Meese Eckart , Lenhof Hans-Peter
Published: December 2006

Background

The development of effective frameworks that permit an accurate diagnosis of tumors, especially in their early stages, remains a grand challenge in the field of bioinformatics. Our approach uses statistical learning techniques applied to multiple antigen tumor antigen markers utilizing the immune system as a very sensitive marker of molecular pathological processes. For validation purposes we choose the intracranial meningioma tumors as model system since they occur very frequently, are mostly benign, and are genetically stable.

Results

A total of 183 blood samples from 93 meningioma patients (WHO stages I-III) and 90 healthy controls were screened for seroreactivity with a set of 57 meningioma-associated antigens. We tested several established statistical learning methods on the resulting reactivity patterns using 10-fold cross validation. The best performance was achieved by Naïve Bayes Classifiers. With this classification method, our framework, called Minimally Invasive Multiple Marker (MIMM) approach, yielded a specificity of 96.2%, a sensitivity of 84.5%, and an accuracy of 90.3%, the respective area under the ROC curve was 0.957. Detailed analysis revealed that prediction performs particularly well on low-grade (WHO I) tumors, consistent with our goal of early stage tumor detection. For these tumors the best classification result with a specificity of 97.5%, a sensitivity of 91.3%, an accuracy of 95.6%, and an area under the ROC curve of 0.971 was achieved using a set of 12 antigen markers only. This antigen set was detected by a subset selection method based on Mutual Information. Remarkably, our study proves that the inclusion of non-specific antigens, detected not only in tumor but also in normal sera, increases the performance significantly, since non-specific antigens contribute additional diagnostic information.

Conclusion

Our approach offers the possibility to screen members of risk groups as a matter of routine such that tumors hopefully can be diagnosed immediately after their genesis. The early detection will finally result in a higher cure- and lower morbidity-rate.
Chemoresistance induces enhanced adhesion and transendothelial penetration of neuroblastoma cells by down-regulating NCAM surface expression
Authors: Blaheta Roman A , Daher Frederick H , Michaelis Martin , Hasenberg Christoph , Weich Eva M , Jonas Dietger , Kotchetkov Rouslan , Doerr Hans Willhelm , Cinatl Jindrich
Published: December 2006

Background

Drug resistance to chemotherapy is often associated with increased malignancy in neuroblastoma (NB). One explanation for the link between resistance and malignancy might be that resistance facilitates cancer progression and invasion. To investigate this hypothesis, adhesion, transendothelial penetration and NCAM (CD56) adhesion receptor expression of drug-resistant versus drug-sensitive NB tumor cells were evaluated.

Methods

Acquired drug resistance was mimicked by exposing parental UKF-NB-2, UKF-NB-3 or IMR-32 tumor cells to increasing concentrations of vincristine- (VCR) or doxorubicin (DOX) to establish the resistant tumor cell sublines UKF-NB-2VCR, UKF-NB-2DOX, UKF-NB-3VCR, UKF-NB-3DOX, IMR-32VCR and IMR-32DOX. Additionally, the malignant behaviour of UKF-NB-4, which already possessed the intrinsic multidrug resistance (MDR) phenotype, was analyzed. UKF-NB-4 exposed to VCR or DOX were designated UKF-NB-4VCR or UKF-NB-4DOX. Combined phase contrast – reflection interference contrast microscopy was used to separately evaluate NB cell adhesion and penetration. NCAM was analyzed by flow cytometry, western blot and RT-PCR.

Results

VCR and DOX resistant tumor sublines showed enhanced adhesion and penetration capacity, compared to their drug naïve controls. Strongest effects were seen with UKF-NB-2VCR, UKF-NB-3VCR and IMR-32DOX. DOX or VCR treatment also evoked increased invasive behaviour of UKF-NB-4. The process of accelerated tumor invasion was accompanied by decreased NCAM surface and protein expression, and down-regulation of NCAM coding mRNA. Transfection of UKF-NB-4VCR cells with NCAM cDNA led to a significant receptor up-regulation, paralleled by diminished adhesion to an endothelial cell monolayer.

Conclusion

It is concluded that NB cells resistant to anticancer drugs acquire increased invasive capacity relative to non-resistant parental cells, and that enhanced invasion is caused by strong down-regulation of NCAM adhesion receptors.
An ecometric analysis of neighbourhood cohesion
Authors: Fone David L , Farewell Daniel M , Dunstan Frank D
Published: December 2006

Background

It is widely believed that the social environment has an important influence on health, but there is less certainty about how to measure specific factors within the social environment that could link the neighbourhood of residence to a health outcome. The objectives of the study were to examine the underlying constructs captured by an adapted version of Buckner's neighbourhood cohesion scale, and to assess the reliability of the scale at the small-area-level by combining ecometric methodology with ordinal modelling of a five-point scale.

Methods

Data were analysed from 11,078 participants in the Caerphilly Health and Social Needs Study, who were sampled from within 325 UK census enumeration districts in Caerphilly county borough, Wales, UK. The responses of interest came from 15 question items designed to capture different facets of neighbourhood cohesion. Factor analysis was used to identify constructs underlying the neighbourhood cohesion item responses. Using a multilevel ecometric model, the variability present in these ordinal responses was decomposed into contextual, compositional, item-level and residual components.

Results

Two constructs labelled neighbourhood belonging and social cohesion were identified, and variability in both constructs was modelled at each level of the multilevel structure. The intra-neighbourhood correlations were 6.4% and 1.0% for the neighbourhood belonging and social cohesion subscales, respectively. Given the large sample size, contextual neighbourhood cohesion scores can be estimated reliably. The wide variation in the observed frequency of occurence of the scale item activities suggests that the two subscales have desirable ecometric properties. Further, the majority of between-neighbourhood variation is not explained by the socio-demographic characteristics of the individual respondents.

Conclusion

Assessment of the properties of the adapted neighbourhood cohesion scale using factor analysis and ecometric analysis extended to an ordinal scale has shown that the items allow fine discrimination between individuals. However, large sample sizes are needed in order to accurately estimate contextual neighbourhood cohesion. The scale is therefore appropriate for use in the measurement of neighbourhood cohesion at small-area-level in future studies of neighbourhoods and health.
17β-estradiol effects on human coronaries and grafts employed in myocardial revascularization: a preliminary study
Authors: Polvani Gianluca , Barili Fabio , Rossoni Giuseppe , Dainese Luca , Ossola Manuela Wally , Topkara Veli K , Grillo Francesco , Penza Eleonora , Tremoli Elena , Biglioli Paolo
Published: December 2006

Background

This study was undertaken to compare the in vitro effects of 17β-estradiol on human epicardial coronary arteries, resistance coronary arteries and on arterial vessels usually employed as grafts in surgical myocardial revascularization.

Methods

Coronary artery rings (descending coronary artery, right coronary artery, circumflex coronary artery, first septal branch) and arterial graft rings (internal thoracic artery, gastro-epiploic artery) obtained from human heart donors with heart not suitable to cardiac transplantation were connected to force transducer for isometric force recording. Precontracted specimens with and without endothelium were exposed to increasing concentration of 17β-estradiol (3–30–300–3000 nmol/l) and to vehicle (0.1% v/v ethanol). We also evaluated the effects of 17β-estradiol on vessels before and 20 minutes after exposure to L-monomethyl-arginine and indomethacin.

Results

17β-estradiol induced a significant relaxation in all precontracted vessels (mean maximum effect: 78,6% ± 8,5). This effect was not different among the different rings and was not related to the presence of endothelium. N-monomethyl-L-arginine and indomethacin did not modify 17β-estradiol relaxant effect.

Conclusion

The vasodilator action of the 17β-estradiol is similar on coronary arteries, resistance coronary arteries and arterial vessels usually employed as grafts in myocardial revascularization.
Genetic polymorphisms in the cyclooxygenase-2 gene, use of nonsteroidal anti-inflammatory drugs, and breast cancer risk
Authors: Shen Jing , Gammon Marilie D , Terry Mary Beth , Teitelbaum Susan L , Neugut Alfred I , Santella Regina M
Published: December 2006

Introduction

The association between use of nonsteroidal anti-inflammatory drugs (NSAIDs) and breast cancer risk remains unclear. Inconsistencies in previously reported findings may be partly due to differences in expression of cyclooxygenase (COX)-2. We hypothesized that genetic polymorphisms (COX-2 .926, COX-2 .5209, and COX-2 .8473) may reduce overall breast cancer risk or risk for subtypes of breast cancer by modulating the inflammatory response and may interact with aspirin or any NSAID use.

Methods

We conducted a population-based, case-control study in which we genotyped 1,067 breast cancer cases and 1,110 control individuals included in the Long Island Breast Cancer Study Project.

Results

No major effects of the three COX-2 variant alleles on breast cancer risk were found. A total of eight distinct haplotypes and 18 diplotypes were observed in the population. Overall, no significant associations between COX-2 haplotypes/diplotypes and breast cancer risk were observed. Among women who used aspirin or any NSAID there was little evidence for an interaction with the at-risk COX-2 genotypes, with one exception. Among women with hormone receptor positive breast cancer, the reduced risk for any NSAID use was only evident among those who had at least one variant C allele of COX-2 .8473 (odds ratio = 0.7, 95% confidence interval = 0.5 to 1.0; P for the interaction = 0.02). There was no corresponding interaction for aspirin use, possibly because of limited power.

Conclusion

These data provide modest evidence that the C allele of COX-2 .8473 may interact with NSAIDs to reduce risk for hormone receptor positive breast cancer.
Gene function and expression level influence the insertion/fixation dynamics of distinct transposon families in mammalian introns
Authors: Sironi Manuela , Menozzi Giorgia , Comi Giacomo P , Cereda Matteo , Cagliani Rachele , Bresolin Nereo , Pozzoli Uberto
Published: December 2006

Background

Transposable elements (TEs) represent more than 45% of the human and mouse genomes. Both parasitic and mutualistic features have been shown to apply to the host-TE relationship but a comprehensive scenario of the forces driving TE fixation within mammalian genes is still missing.

Results

We show that intronic multispecies conserved sequences (MCSs) have been affecting TE integration frequency over time. We verify that a selective economizing pressure has been acting on TEs to decrease their frequency in highly expressed genes. After correcting for GC content, MCS density and intron size, we identified TE-enriched and TE-depleted gene categories. In addition to developmental regulators and transcription factors, TE-depleted regions encompass loci that might require subtle regulation of transcript levels or precise activation timing, such as growth factors, cytokines, hormones, and genes involved in the immune response. The latter, despite having reduced frequencies of most TE types, are significantly enriched in mammalian-wide interspersed repeats (MIRs). Analysis of orthologous genes indicated that MIR over-representation also occurs in dog and opossum immune response genes, suggesting, given the partially independent origin of MIR sequences in eutheria and metatheria, the evolutionary conservation of a specific function for MIRs located in these loci. Consistently, the core MIR sequence is over-represented in defense response genes compared to the background intronic frequency.

Conclusion

Our data indicate that gene function, expression level, and sequence conservation influence TE insertion/fixation in mammalian introns. Moreover, we provide the first report showing that a specific TE family is evolutionarily associated with a gene function category.